Chapter 1 (The Solid State)
1 Mark Questions
4 marks
1. Name the type of point defect that occurs in a crystal of ZnS.
2. How many octahedral voids are there in one mole of a compound having
cubic close packed Structure?
3. What is the C.N. of each type of ions in a rock salt type crystal structure?
4. What is the total no. of atoms per unit cell in a FCC structure?
5. What type of substance exhibits antiferromagnetism?
6. What type of alignment in crystals make them ferromagnetic?
7. Name an element with which Si should be doped to give n- type semiconductor.
8. What is F- centre?
9. Why is glass considered a supercooled liquid?
10. What is the two dimensional coordination no. of a sphere in square close packing?
11. How do metallic & ionic substance differ in conducting electricity?
12. Which point defect of its crystals decreases the density of a solid?
13. Which point defect in crystal increases the density of solid?
14. Which point defect in crystal does not alter the density of the relevant solid?
15. What is the total no. of atoms per unit cell in a FCC structure?
16. What is the no. of atoms in a BCC unit cell of a crystal?
17. What type of interaction hold the molecules together in a polar molecular solid?
18. What type of semiconductor is obtained when Si is doped with As?
19. What is the no. of atoms in a unit cell of a simple cubic crystal?
20. Why LiCl acquires pink colour when heated in Li vapours?
21. Calculate the packing efficiency of a metal crystal for a simple cubic lattice.
22. Crystalline solids are anisotropic in nature. What does this statement mean?
23. What is meant by an intrinsic semi conductors?
24. Give an example of an ionic compound which shows Frenkel defect.
25. How may the conductivity of an intrinsic semiconductor be increased?
26. What are n-type semiconductors?
27. Which stoichiometric defect increases the density of a solid?
28. What is meant by doping?
29. What is meant by the term ‘forbidden zone’ in reference to band theory of solids?
30. Define paramagnetism with an example.
31. Write distinguishing feature of metallic solids from an ionic solid.
32. What is the formula of a compound in which the element Y forms ccp lattice and
atoms of X occupy 1/3rd of tetrahedral voids ?
33. What type of stoichiometric defect is shown by AgCl ?
34. What is the relationship between edge length ‘a’ and atomic radius ‘r’ in bcc lattice?
35. Why common salt is sometimes yellow instead of being pure white?
36. In reference to crystal structure , explain the meaning of coordination number.
2, 3 Marks Questions
1. Name the crystal defect which reduces the density of an ionic solid? What type of ionic
solids show this defect?
2. Aluminium crystallizes in an fcc structure. Atomic radius of the metal is 125 pm. What is
the length of the side of the unit cell of the metal?
3. Account for the following:
(i) Silicon is an insulator but silicon doped with phosphorus acts as a semi-conductor.
(ii) Some of the glass objects recovered from ancient monuments look milky instead of
being transparent.
4. Equal no. of cation & anion missing in the diagram is given.
(i)
What are these types of vacancy defects called?
(ii)
How is the density of crystal affected by these defects?
(iii)
Name one ionic compound which can show this type of defect in crystalline state.
(iv)
How is the stoichiometry of compound affected?
5. Analysis shows that MO has M 0.96 O 1.00 Calculate % M 2+ & M 3+ ions in the crystal.
6. In an ionic compound N- form cubic close type packing while the cation M+ ions occupy
one third of the tetrahedral voids. Deduce the formula of compound & the C.N. of M+
ions.
7. A compound contains 2 types of atoms X & Y. It crystallizes in a cubic lattice with atom
X at the corner & Y at body centres. What is the simplest possible formula of
compound.
8. An element X with an at. Mass 60 g/mol has density 6.23 g/cm3 If the edge length of
cubic unit cell is 400pm.Identify the type of cubic unit cell. Calculate the radius of an
atom of this element.
9. An element crystallizes in BCC structure.If the edge length of the cell is 1.469 x 10 -10 m.
& density is 19.3 g/cm3. Calculate the at. Mass of this element. Also calculate the radius
of an atom of this element.
10. What is a semiconductor? Describe the two main types of semiconductors & explain
mechanism for their conduction.
11. Reasons: (i) Frenkel defects are not found in alkali metal halides.
(ii) Schottky defects lower the density of related solids.
(iii) Impurity doped Si is a semiconductor.
12. Explain (i) Ferromagnetism (ii) Paramagnetism (iii) Ferrimagnetism.
13. Ag crystallizes in FCC lattice. The edge length of its unit cell is 4.077 x 10 -8 cm. & its
density is 10.5 g/cm3 Calculate the at. Mass of Ag.
14. Explain (i) F-centre (ii)Paramagnetism (iii) Frenkel defect (iv) Schottky defect
15. Reason: (i) Fe3O4 is ferromagnetic at room temperature but becomes paramagnetic at
850K.
(ii) ZnO on heating becomes yellow.
(iii) Frenkel defect does not change the density of AgCl crystal
16. With the help of suitable diagram, on the basis of Band theory, explain the difference
between (a)A conductor & an insulator
(b) A conductor & semiconductor.
17. Ag crystallizes with FCC unit cells. Each side of the unit cell has a length of 409 pm
what is the radius of an atom of Ag?
18. Fe has a BCC unit cell with a cell edge of 286.65 pm. The density of Fe is 7.87 g/cm3.
Calculate Avogadro’s no. (at. Mass Fe=56 g/mol)
19. How are the following properties of crystals affected by Schottky & Frenkel defects? (i)
density (ii) electrical conductivity
20. (a) In reference to crystal structure, explain the meaning of C.N.
(b) What is the no. of atoms in a unit cell of FCC & BCC structure
21. Cu crystallizes into a FCC lattice with edge length 3.61 x 10 -8 cm. Calculate the density
of Cu? (Cu = 63.5 g/mol)
22. The density of Cu metal is 8.95 g / cm3 If the radius of Cu atom be 127.8pm is the unit
cell simple cubic , BCC or FCC ( Cu = 63.54 g /mol , NA = 6.02 x 10 23 mol-1)
23. Ag crystallizes in FCC cubic unit cell. If the edge length of unit cell is 4.07x10-8 cm. and
density 10.5 g/cm3. Calculate the atomic mass of Ag(NA = 6.02 x 10 23 mol-1)
24. In one unit cell of CaF2 there are 4Ca2+ and 8 F- ions.Ca2+ are arranged in FCC lattice.
The F- ions fill all tetrahedral holes in the FCC lattice of Ca2+ ions, The edge of the unit
cell is 5.46 x 10 -8 cm in length, the density of solid is 3.18 g/cm3.Calculate Avogadro’s
no. (M.M. of CaF2 =78.08 g/mol)
25. Fe has a BCC unit cell with a cell edge of 286.65 pm. The density of Fe is 7.87 g/cm3.
Calculate Avogadro’s no. (at. Mass Fe=56 g/mol)
26. Sodium crystallizes in BCC unit cell. Calculate the approximate no. of unit cells in 9.2 g
of sodium (Na = 23)
27. What is a semiconductor? Describe the two main types of semiconductors.
28. KF has CCP structure. Calculate the radius of unit cell if the side of the cube or edge
length is 400 pm. How many F- ions and octahedral voids are there in this unit cell.
29. (a) Why is Frenkel defect found in AgCl?
(b) What is the difference between P doped and Ga doped semiconductors
30. Au (at.mass 197 u , at. radius= 0.144 nm) crystallizes in a FCC unit cell. Determine the
density of Au.(NA = 6.022 x 10 23 mol -1)
31. Classify each as being either p-type or n-type semiconductor. Give reason.
(a)Si doped with In (b) Si doped with P
32. Explain how you can determine the at. mass of an unknown metal if you know its mass,
density and the dimensions of unit cell of its crystal.
33. Define the following terms in relation to crystalline solids (a) Unit cell (b) co-ordination
no. Give one example in each case.
34. The density of lead is 11.35 g/cm3 and the metal crystallizes with FCC unit cell.
Estimate the radius of lead atom. (Pb = 207 g/mol)
35. Al crystallizes in CCP. Radius of atom in metal is 125 pm.
(a) What is the length of side of unit cell?
(b) How many unit cells are there in 1cm3 of Al?
36. How are the following properties of crystals affected by Schottky and Frenkel defects
(i) Density (ii) Electrical conductivity?
37. Copper crystallizes into an FCC lattice and has a density of 8.930g/cm3 at 293 K .
Calculate the radius of copper atom. (Cu= 63.5 g/mol , NA = 6.022 x 1023 /mol)
38. Iron has BCC unit cell with cell dimension of 286.65 pm. Density of iron is 7.87
g/cm3.use this information to calculate Avogadro’s number. (at.mass of Fe = 56.0u)
39. Tungsten crystallizes in body centred cubic unit cell.If the edge of the unit cell is
316.5 pm. What is the radius of tungsten atom?
40. Silver crystallizes in FCC unit cell. If the radius of silver atom is 145 pm, what is the
Length of each side of unit cell?
41. Account for the following:
(i) schottky defects lower the density related solids.
(ii) Conductivity of silicon increases on doping it with phosphorus
42. (a) why does presence of excess of lithium makes LiCl crystals pink?
(b) a solid with cubic crystal is made of two elements P and Q. atoms of Q are at the
corners of the cube and P at the body centre . what is the formula of the compound.
43. (a) what change occurswhen AgCl is doped with CdCl2?
(b) what type of semiconductor is produced when silicn is doped with boron?
44. An element with molar mass 27 g mol–1 forms a cubic unit cell with edge length
4.05 × 10–8 cm. If its density is 2.7 g cm–3, what is the nature of the cubic unit cell ?
45. Examine the given defective crystal A+ B- A+ B- A+
B- O B- A+ BA+ B- A+ O A+
B- A+ B- A+ BAnswer the following questions: (i) What type of stoichiometric defect is shown by
the crystal ?
(ii) How is the density of the crystal affected by this defect ?
(iii) What type of ionic substances show such defect ?
Chapter 2 (Solutions)
1 Mark Questions
5 marks
1. What is Van’t Hoff factor for a compound which undergoes tetramerization in an organic
compound ?
2. What is reverse osmosis?
3. State Henry’s law about partial pressure of a gas in a mixture.
4. Define the term Osmotic Pressure.
5. State the main advantage of molality over molarity as the unit of concentration.
6. State Raoult’s law for a solution of volatile liquids.
7. Define an ideal solution.
8. Define the term, mole fraction.
9. Why 1M aqueous solution of a solute is more concentrated than the 1m aqueous solution
of same solute?
10. Why ethyl alcohol and water cannot be separated into pure components by fractional
distillation?
11. Why do aquatic species feel more comfortable in the lakes in winter than in summer?
12. Addition of 2 Hgl to aq. KI solution shows an increase in V.P. why?
13. What happens when we place the blood cell in saline water solution (hypertonic solution)
? Give reason.
14. What are isotonic solutions ?
15. A and B liquids on mixing produce a warm solution. Which type of deviation from
Raoult’s law is there?
2, 3 Marks Questions
1. 18g of glucose, C6H12O6 (Molar Mass= 180g mol-1) is dissolved in 1Kg of water in a
sauce pan. At what temperature will this solution boil?
2. Calculate the mass of compound (molar mass = 256 gmol-1) to be dissolved in 75 g of
benzene to lower its freezing point by 0.48 K (Kf = 5.12 K kg mol-l).
3. Define an ideal solution and write one of its characteristics.
4. Determine the osmotic pressure of a solution prepared by dissolving 2.5× 10−2 g of
K2SO4 in 2L of water at 25 ○ C, assuming that it is completely dissociated. (R=0.0821 L
atm K-1mol-1, Molar mass of K2SO4=174g mol-1).
5. Vapour pressure of water at 20○C is 17.5 mm Hg. Calculate the vapour pressure of water
at 20○C when 15 g of glucose (Molar mass = 180 g mol-1) is dissolved in 150 g of water.
6. Define the following terms :
7. (i) Mole fraction (x) (ii) Molality of a solution (m)
8. A 5 percent solution (by mass) of cane-sugar (M.W. 342) is isotonic with 0.877%
solution of substance X. Find the molecular weight of X.
9. A 5% solution (by mass) of cane-sugar (C12H22O11) in water has f.p. of 271 K. Calculate
the f.p. of 5% glucose (C6H12O6) in water, if the f.p. of water is 273·15K.
10. What is meant by positive deviations from Raoult’s law ? Give an example. What is the
sign of ∆mixH for positive deviation ?
11. Define azeotropes. What type of azeotrope is formed by positive deviation from Raoult’s
law? Give an example.
12. 3.9 g of benzoic acid dissolved in 49 g of benzene shows a depression in freezing point of
1.62 K. Calculate the van’t Hoff factor and predict the nature of solute (associated or
dissociated). (Given : Molar mass of benzoic acid = 122 g mol–1, Kf for benzene = 4.9
K kg mol–1)
13. Diagram of Reverse Osmosis Plant given. (i)Name the process occurring in the above
plant.
(ii) To which container does the net flow of solvent take place?
(iii) Name one SPM which can be used in this plant.
Give the practical use of the plant.
14. Heptane & Octane form an ideal solution at 373 K. The V.P. of the pure
liquid at this temperature is 105.2 KPa & 46.8 KPa resp. if the solutioncontains 25g of
heptanes & 28.5 g of octane. Calculate (i) V.P. exerted by heptanes
(ii) V.P. exerted by solution (iii)mole fraction of octane in the V.P.
15. Ethylene glycol (M.M. = 62 g/mol) is an antifreeze. Calculate F.P. of solution
containing 12.4 g of substance in 100 g of water. Would it be advisable to
keep the substance in the car radiator during summer ?
(kf for water = 1.86 KKg/mol , Kb for water= 0.512 KKg/mol)
16. Reason: (a) At higher altitude people suffer from a disease called anoxia. In this disease
they become weak & can’t think clearly.
(b) When HgI2 is added to KI , the Freezing Point is raised?
17. (a) Which aqueous solution has higher concentration 1M or 1 molal solution of
the
same mole? Give reason.
(b) 0.5 g KCl was dissolved in 100 g water & the solution originally at 20 0C, froze at
-0.24 0C Calculate % ionization of salt (Kf :1.86 KKg /mol)
18. State Henry’s law correlating the pressure of a gas & its solubility in a solvent & mention
two applications for the law.
19. Calculate the temp. at which a solution containing 54 g of glucose (C6H12O6) in 250 g of
water will freeze (Kf for water =1.86 KKg/mol)
20. State Raoult’s law for solution of volatile liquids taking suitable examples. Explain the
meaning of positive & negative deviations from Raoult’law.
21. Define the term O.P. Describe how the mol.mass of a substance can be determined by a
method based on measurement of O.P.
22. A solution containing 8 g. of substance in 100 g of diethyl ether boils at 36.86 0C
whereas pure ether boils at 35.6 0C Determine the mol.mass o solute.
( Kb for ether = 2.02 KKg/mol)
23. Calculate the temperature at which a solution containing 54 g of glucose (C6H12O6) in
250 g of water will freeze.(Kf for water = 1.86 KKg/mol)
24. (a) State how the V.P,of a solvent is affected when a non volatile is dissolved in it.
( b )A 5% solution ( by mass ) of cane sugar in water has a F.P. 271K, Calculate the F.P.
of 5% (by mass) solution of glucose in water. (F.P. of water is 273.15K,M.M.of sugar =
342g/mol & M.M. of glucose = 180 g/mol)
25. ) (a) If density of water of a lake is 1.25 g/mol & 1 kg of lake water contains 92g of Na+
ions. Calculate the molarity of Na+ ions in this lake water.
(b)Calculate the mass of a non volatile solute ( mol mass 40 g/mol) which should be
dissolved in 114 g of octane to reduce its V.P. to 80 %
(M.M. of octane = 114 g /mol )
26. What is meant by negative deviation from Raoult’s law? Draw diagram to illustrate the
relationship between V.P. & mole fraction of components in a solution to represent
negative deviation.
27. The b.p. elevation of 0.3g of acetic acid in 100g benzene is 0.0633K. Calculate the molar
mass of acetic acid from this data.What conclusion can you draw about the molecular
state of the solute in solution?
(Kb for benzene = 2.53KKg/mol)
28. Distinguish between the terms molality & molarity.Under what conditions are the
molarity & molality of a solution nearly the same?
29. The F.P. of a solution containing 0.2 g of acetic acid in 20 g of benzene is lowered by
0.450 Calculate (i) the mol.mass of acetic acid from this data.
(ii) van’t Hoff factor
(Kf benzene = 5.12 K Kg/mol) What conclusion can you draw from the value of van’t
Hoff factor obtained.
30. What are non ideal solutions? Give one example.Explain as to why non ideal solution
deviate from Raoult’s law.
31. Calculate the amount of KCl which must be added to 100 g of water so that water freezes
at –20C Assume that KCl undergoes complete dissociation.
(Kf = 1.86KKg/mol , K=39,Cl=35.5)
32. Differentiate between molality & molarity of solution.What is the effect of change in
temp. of a solution on its molality or molarity?
33. Calculate F.P. depression expected for 0.0711 m aq.solution of Na2SO4. If this solution
actually freezes at –0.320C What would be the value of van’t Hoff factor (Kf for water
= 1.86KKg/mol)
34. Calculate the amount of NaCl which must be added to 1 kg of water is depressed by 3K.
( Kf = 1.86KKg/mol, Na=23,Cl=35.5)
35. A solution of urea in water has a b.p. 373.128K Calculate the F.P. of the same solution.
(Kf = 1.86Km-1 , Kb=0.52Km-1)
36. 0.1 mole of acetic acid was dissolved in 1 kg of benzene. Depression in F.P. of benzene
was determined to be 0.256K. What is the state of solution?
(Kf for benzene = 5.12K/m)
37. Define the term osmosis and osmotic pressure.What is the advantage of using O.P. as
compared to other colligative properties for the determination of molar masses of solute
in solution.
38. What mass of NaCl ( M.M. = 58.5 g/mol) must be dissolved in 65 g of water to lower the
F.P. by 7.5 0C ? The F.P. depression constant Kf for water is
1.86 Kkg/mol. Assume that van’t Hoff factor for NaCl is 1.87.
39. What mass of ethylene glycol (M.M = 62 g/mol) must be added to 5.5 kg of water to
lower the F.P. of water from 0 0 C to – 10 0C ? (Kf for water = 1.86 Kkg/mol)
40. 15 g of an unknown molecular substance was dissolved in 450 g of water . The resulting
solution freezes at – 0.340C What is the molar mass of substance?
(Kf for water = 1.86 Kkg/mol)
41. Non ideal solution exhibits either +ve or –ve deviation from Raoult’s law.What are these
deviations and why they are caused?Explain with one example of each.
42. A solution prepared by dissolving 1.25 g of oil of winter green in 99 g benzene has a
b.p. of 80.31 0C.Determine the molar mass of this compound. ( b.p. of pure benzene =
80.10 0C. and Kb for benzene = 2.530C kg/mol.)
43. A solution of glycerol(M.M. = 92 g/mol) in water was prepared by dissolving some
glycerol in 500 g of water.This solution has a b.p. of 100.42 0C What mass of glycerol
was dissolved to make the solution. (Kb for water = 0.512 Kkg/mol)
44. State Raoult’s law for a solution containing volatile liquids.Explain with suitable example
the concept of max. boiling azeotrope.
45. On dissolving 19.5 g of CH2FCOOH in 500 g of water a depression of 1 0C inF.P. of
water is observed. Calculate the van’t Hoff factor and dissociation constant of flouro
acetic acid, Given Kf = 1.86Kkg/mol
46. Determine the molarity of an antifreeze solution containing 250 g water mixed with 222
g ethylene glycol. The density of the solution is 1.07 g/ml.
47. An aqueous solution containing urea was found to haveb.p. more than the normal b.p. of
water(313.13K)When the same solution was cooled it was found that its F.P, is les than
the normal b.p. of water(273.13K) Explain these observations.
48. State the following
(i)Raoult’s law in its general formin reference to solutions
(ii)Henry’s law about partial pressure of a gas in a mixture
49. A solution prepared by dissolving 8.95 mg of a gene fragment in 35 ml of Water has an
O.P. of 0.335 Torr at 25 0 V Assuming that the gene fragment is a non
electrolyte,calculate its molar mass.
50. What mass of NaCl must be dissolved in 65 g of water to lower the F.P. of water by7.5
0C?TheKf for water is1.86 0C/m. Assume van’t Hoff factor for NaCl is1.87(M.M. of
NaCl is 1.87(M.M. of NaCl=58.5 g)
51. What would be the M.M. of a compound if 6.21 g of it dissolved in 24 g of chloroform a
solution that has a b.p. of 68.04 0C. The b.p. of pure chloroform is 61.7 0C . ( Kb for
chloroform = 3.63 0C/m)
52. Differentiate between molarity and molality for a solution. Explain how molarity value
of a solution can be converted into its molality.
53. A 0.561m solution of an unknown electrolyte depress the F.P. of water by
2.93 0C. What is van’t Hoff factor for this electrolyte. (Kf = 1.86 0C/kg/mol)
54. 0.1 mole of acetic acid was dissolved in 1 kg of benzene. Depression in F.P. of benzene
was determined to be 0.256 K . What conclusion can you draw about the state of the
solute in solution (Kf for benzene = 5.12 K/m)
55. a solution of glycerol (C3H8O3) in water was prepared by dissolving some glycerol in
500 g of water. this solution has b.p.of 100.420C.what mass of glycerol was dissolved to
make this solution? (Kb for water = 0.512 K kg /mol. )
5-Marks Questions
1. (i) Derive relationship between relative lowering of V.P. & mole fraction of the volatile
liquid
(ii)
Benzoic acid completely dimerises in benzene. What will be the V.P. of a
solution containing 61 g of benzoic acid per 500 g benzene when the V.P. of pure
benzene at the temp. of experiment is 66.6 Torr.
(iii) What would have been the V.P. in the absence of dimerization.
(iv)
Derive a relationship between mole fraction & V.P. of a component of an ideal
solution in the liquid phase & vapour phase.
2. (i) State Henry’s law and mention its two important applications.
(ii) Henry’s law constant for CO2 dissolving in water is 1.67 x 10 8 Pa at 298 K. Calculate
the quantity of CO2 in 1L of soda water when packed under 2.5 atm CO2 pressure at 298
K.
3. (a) The depression of F.P. of water observed for the same molar concn of acetic acid,
trichloroacetic acid & triflouroacetic acid increases in the order as stated above .Explain .
(b) Calculate the depression in F.P. of water when 20 g of CH3CH2CH(Cl) COOH is
added to 500 g of water.(Ka =1.4 x10-3, Kf= 1.86KKg /mol)
4. (a) What is meant by (i) Colligative property (ii) molality of solution
(b)What concentration of N2 should be present in a glass of water at room temp.?Assume
temp. of 250C , a total pressure of 1 atm & mole fraction of N2 in air of 0.78 (KH for N2 =
8.42 x 10 –7 M/mmHg)
5. (a) Define (i) mole fraction (ii) van’t Hoff factor
6.
7.
8.
9.
(b) 100mg of a protein is dissolved in enough water to make 10 ml of a solution.If this
solution has an O.P. of 13.3 mm Hg at 250CWhat is the molar mass of protein? (R= 0.0821
Latm/mol/K & 760 mm Hg=1atm)
(a)Menthol is a crystalline substance with peppermint taste. A 6.2% solution of menthol in
cyclohexane freezes at-1.950 C. Determine the formula mass of menthol.The F.P. and
molal depression constant of cyclohexane are 6.5 0C and 20.2 K m-1 respectively,
(b) State Henry’law and mention its two important applications.
( c ) Which of the following has higher b.p. and why? 0.1M NaCl or 0.1M glucose
(a) Define azeotropes and explain briefly minimum boiling azeotrope by taking suitable
example.
( b ) The V.P. of pure liquids A and B are 450 mm and 700 mm of Hg respectively at 350
K.Calculate the composition of liquid mixture if total V.P, is 600 mmHg.
Also find the composition of the mixture in vapour phase.
(a) explain the following:
(i)Henry’s law about dissolution of gases in a liquid
(ii)Boiling point elevation constant for a solvent
(b)a solution of glycerol (C3H8O3) in water was prepared by dissolving some glycerol in
500 g of water. this solution has b.p.of 100.420C.what mass of glycerol was dissolved to
make this solution? (Kb for water = 0.512 K kg /mol. )
(a) Define the following terms:
(i)
Van’t Hoff factor
(ii) Mole fraction
(iii) Ebullioscopic constant
(b) State Raoult’s law
(c) the density of water of a lake is1.25 g/ml and 1kg of this water contains 92 g
ions.What is the molarity of Na+ ions in the water of the lake?(at.massNa=23u )
of Na+
10. (a) state Raoult’s law for a solution containing volatile components. How does Raoult’s
law become a special case of Henry’s law?
( b) 1.00 g of a non electrolyte solute dissolved in 50 g of benzene lowered the freezing
point of benzene by 0.40 K. Find the molar mass of the solute. (Kf for benzene = 5.12 Kkg
mol -1)
11. (a) define the following terms:
(i)
Ideal solution
(ii)
Azeotrope
(iii) Osmotic pressure
(b) a solution of glucose (C6H12O6) in water is labeled as 10 % by weight. What would be
the molality of the solution?(molar mass of glucose = 180 g mol -1)
12. (a) define the following terms:
(i)
Mole fraction
(ii)
Ideal solution
(b) 15 g of an unknown molecular material is dissolved in 450 g of water.
the resulting solution freezes at -0.340 C. what is the molar mass of the material?(Kf for
water = 1.86 Kkg /mol)
Chapter: 3
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
(Electrochemistry)
1-Mark Questions
5 marks
What is primary cell? Give one example
Express the relation between conductivity & molar conductivity of a solution.
State Kohlrausch law of independent migration of ions.
What is meant by Limiting molar conductivity?
Write the product obtained at anode on electrolysis of conc. H2SO4 using Pt electrode.
Express the relation between conductivity and molar conductivity of a
Solution held in a cell.
What is meant by cell constant?
What is the role of ZnCl2 in a dry cell?
What are secondary cells?
Why does a dry cell become dead after a long time even if it has not been used?
2, 3 Marks Questions
1. The conductivity of a 0.2M soln. of KCl at 298 K is 0.0248 Scm-1. Calculate its molar
conductivity.
2. Molar conductivity of a 1.5 M solution of an electrolyte is found to be 138.9 Scm2 /mol.
Calculate the conductivity of this solution.
3. The electrical resistance of a column of 0.05 M NaOH solution of diameter 1 cm, length 50 cm is
5.55 x 10 3 ohm. Calculate its resistivity, conductivity and molar conductivity.
4. Express the relation among cell constant, resistance of the solution in the cell and conductivity of
the solution. How is molar conductivity of a solution related to its conductivity?
5. Calculate emf of the following cell at 298 K
Zn/Zn2+ (10-4 M) ||Cu 2+(10-2M) /Cu
Given E○ Zn2+/Zn=-0.76 V E○ Cu2+/Cu=+0.34V
6. The resistance of cond. Cell containing 0.001 M KCl soln. at 298 K is 1500 ohm What is the
cell const. if the conductivity of 0.001 M soln. at 298 K is 0.146 x 10 –3 S cm-1
7. Conductivity of 0.00241M acetic acid solution is 7.896x10 –5 S cm-1 Calculate its molar
conductivity in this soln. If limiting molar conductivity for acetic acid be 390.5Scm2mol-1 What
would be the its dissociation constant ?
8. Write the chemical equations for the steps involved in rusting of iron. Give one method to
prevent rusting of iron.
9. For the galvanic cell :- Mg(s) + 2Ag+ (0.0001M Mg2+ (0.1M) + 2Ag(s)
E0Mg2+/Mg = -2.36V, E0Ag+/Ag = 0.81V
0
Calculate Ecell,E cell. Write cell representation.Will the reaction be spontaneous?
10. Graph of Molar conductivity vs square root of conc. is given
a. What can you say about the nature of the two electrolytes A & B
b. How do you account for the increases in molar conductivity for strong electrolyte A &
weak electrolyte B on dilution.
11. (a) A current of 1.5 A was passed through an electrolytic cell containing AgNO3 soln. With an
inert electrodes. The weight of Ag deposited was 1.5 g How long did the current flow?
(b) Write the reactions taking place at the anode & cathode in the above cell.
(c) Give reactions taking place at the two electrodes if these are made up of Ag.
12. Three electrolytic cells A,B,C containing soln. of ZnSO4,AgNO3,CuSO4 resp. are connected in
series A steady current of 1.5 A was passed through them until 1.45 g of Ag was deposited at the
cathode of cell B How long did the current flow? What mass of Cu & what mass of Zn were
deposited in the concerned cell?(Ag = 108, Zn = 65.4 ,Cu =63.5)
13. Formulate the galvanic cell in which the following reaction tale place
Zn + 2Ag+  Zn2+ + 2Ag
(i) Which one of its electrodes is negatively charged?
(ii) The reaction taking place at each of its electrode
(iii) The carriers of current within & outside this cell
14. Illustrate with the help of diagram how the molar conductivities of a
(i) Strong electrolyte (ii) weak electrolyte
vary with dilution of soln. Give reason for this variation
15. Calculate E0cell for the following.
2Cr + 3Cd2+  2Cr3+ + 3Cd Calculate ∆G0 & eq. Const. K of the above reaction at 25 0C
(E0Cd2+/Cd = -0.40V, E0Cr3+/Cr = -0.74V)
16. What type of cell is a lead storage battery? Write the anode & cathode reaction & the overall
reactions occurring in the use of a lead storage battery.
17. Two half cell reactions of an electrochemical cells are given below.
MnO4- + 8H++ 5 e  Mn 2+ + 4H2O E0 = +1.51V
Sn2+  Sn 4+ + 2e E0 = +0.15V
Construct the redox equation from the two half cell reactions & predict if this reaction favours
formation of reactants or product shown in the equation.
18. (i) For a weak electrolyte molar conductance in dilute solution increases
sharply as the concentration in solution is decreased . Give reason.
(ii)Write overall cell reaction for lead storage battery when the battery is being charged.
19. Calculate emf of the following cell at 25 0C
Ag(s) /Ag + (10 -3M)// Cu 2+ (10 -1 M)/Cu (s) (Given E 0 Cell= + 0.46 V and log 10 n = n)
20. The standard electrode potential (E0) for Daniell cell is +1.1 V. Calculate the ∆G 0 for the
reaction
Zn(s) + Cu 2+  Zn2+ + Cu(s)
( 1F = 96500 C mol-1)
21. (a) Define molar conductivity of a solution and explain how molar conductivity changes with
change in concentration of a solution for a weak and a strong electrolyte.
(b)The resistance of a conductivity cell containing0.001M KCl solution at 298 K is 1500Ω.What
is the cell constant if the conductivity of 0.001M KCl Solution at 298 K is 0.146 x 10 -3 Scm-1?
22. In the button cell, widely used in watches, the following reaction take place.
Zn +Ag2O + H2O Zn2+ + 2Ag + 2OHDetermine E0 and ∆G0 for the reaction
0
+
0
2+
(E Ag /Ag = +0.80V , E Zn /Zn = -0.76 V)
23. A voltaic cell is set up at 25 0C with the following half cells Al 3+ (0.001 M) and Ni2+ (0.5 M)
Write the cell reaction and determine the cell potential.
(E0 Ni2+/Ni =- 0.258V , E0 Al3+ /Al = -1.66 V)
24. What is nickel-cadmium cell? State its one merit and one demerit over lead storage cell. Write
the overall reaction that occurs during discharging of this cell.
25. Calculate the potential for half cell containing 0.1M K2Cr2O7 (aq) , 0.2M Cr3+(aq)and 1.0 x 10 -4
M H+.The half cell reaction is Cr2O7 2- (aq) + 14 H+(aq) + 6 e-  2 Cr3+(aq) + 7 H2O(l) And the
standard electrode potential is given as E0 = 1.33V
26. Determine the value of Kc and ∆ G0 for Ni + 2Ag +  Ni2+ + 2Ag (E0 cell = 1.05V)
27. The chemistry of corrosion of iron is an electrochemical phenomenon. Explain the reactions
occurring in the corrosion of iron in the atmosphere.
28. A voltaic cell is set up at250Cwith the following half cells Al 3+ (0.001 M) and Ni2+ (0.5 M) Write
the cell reaction and determine the cell potential.(E0 Ni2+/Ni = 0.258V , E0 Al3+ /Al = -1.66 V)
29. Describe the construction of a H2 –O2 fuel cell and the reactions taking place in it.
30. A Cu-Ag cell is set up. The Cu 2+ concentration in it is 0.1M The Ag+ concentration is not
known. The cell potential measured 0.422V Determineconcentration of Ag+ in the cell.
Given: (E0Ag+/Ag = 0.80V,E0 Cu2+/Cu = +0.80V)
31. (a) What is a fuel cell? What is the main advantage?
(b) What are the reactions occurring at the cathode and anode of a Lachlanche cell?
32. Give reasons:
(a)Why does an alkaline medium inhibit the rusting of iron?
(b) Why does a dry cell become dead after a long time even if it has not been used?
(c) Why is Zn better than Sn in protecting iron from corrosion?
33. One half cell in voltaiccell is constructedfrom a silver wire dipped in AgNO3 soln. of unknown
conc.Its other half cell consists of a Znelectrode dipping in 1.0 M soln. of Zn(NO3)2.A voltage of
1.48V is measured for this cell. Calculate [Ag+ ].
(E0Zn2+/Zn = -0.76V, E0Ag+/Ag = 0.80V)
34. Corrosion is essentially an electrochemical phenomenon. Explain the reactions occurring during
the corrosion of iron kept in an open atmosphere.
35. Write the anode and cathode reactions occurring in a commonly used Hg – cell. How is the
overall reaction represented?
36. Given that E0 of metals are K+/K = -2.93V,Ag+/Ag = 0.80V, Cu2+/Cu = 0.34V,Mg2+/Mg = 2.37V,Cr3+/Cr = -0.74V,Fe2+/Fe = -0.44V.
Arrange these metals in increasing order of their reducing power.
37. Two half reactions of an electrochemical cells are given below
MnO4- + 8H+ + 5e  Mn2+ + 4 H2O E0 = +1.51V
Sn2+  Sn4+ + 2e
E0 = +0.15V
Costruct the redox reaction equation from the two half reactions and calculate the cell
potentials and predict if the reaction is reactant or product favoured?
38. One Half cell in a voltaic cell is constructed from Ag wire dipped in AgNO3 solution of
unknown concentration .The other half cell consists of Zn electrode in 0.1M solution of
Zn(NO3)2.A voltage of 1.48V is measured for this cell.Calculate concentration of AgNO3
solution (Given E0Ag+/Ag = 0.80V, E0Zn2+/Zn = - 0.763V)
39. A voltaic cell is set up at 250C with the following half cells Al3+ (0.001M) and Ni2+ (0.5M)
Write equation and determine Ecell. (Given E0Al3+/Al = -1.66 V, E0Ni2+/Ni = - 0.25V)
40. The following curve is obtained when molar conductivity (Λm) is plotted against the
square root of concentration for 2 electrolytes A and B.
(a)
What can you say about the nature of the two electroyltes A and B ? 1
(b)
How do you account for the increase in molar conductivity Λm for the
electrolytes A and B on dilution ?
lm
400
200
A
0.2 ½
C
B
0.4
5 Marks questions
1. (a) Calculate the eq. Const. for the reaction Zn + Cd2+  Zn2+ + Cd
E0Cd2+/Cd = -0.403V, E0Zn2+/Zn = -0.763V
(b) When a current of 0.75A is passed through a CuSO4 solution for 25 min. 0.369 g of Cu is
deposited at the cathode. Calculate at. mass of Cu
(c) Tarnished Ag contains Ag2S Can this tarnish be removed by placing tarnished Ag ware in an
Al pan containing an electrolytic solution such as NaCl.The E0 for half reactions are Ag2S
Ag2S + 2e-  2Ag + S2- is –0.17V
Al3+ +3e-  Al is -1.66V
2.
(a) Calculate ∆G0 for the following reaction at 250C
Au + Ca2+(0.1M)  Au3+(1M) + Ca
E0Au3+/Au = +1.5V, E0Cd2+/Cd = -0.403V
Predict whether the reaction will be spontaneous or not at 250C Which of the above two half
cells will act as an O.A. & which one will be a R.A.
(b) The conductivity of 0.001M acetic acid is 4 x 10 –5 S/cm Calculate the dissociation const. of
acetic acid if limiting molar conductivity for acetic acid is 390.5 Scm2/mol
3. (a) Explain why electrolysis of an aq. Soln. of NaCl gives H2 at cathode & Cl2
at anode. (E0Na+/Na = -2.71V, E0H2O/H2 = -0.83V, E0Cl2/2Cl- = +1.36V
E02H+/1/2O2/H2O = +1.23V)
(b) The resistance of cond. Cell containing 0.05 M soln of an electrolyte X at 400C is 100 ohm
The same cell is filled with 0.01M soln. of electrolyte. Y has a resistance of 50 ohm The cond.
of 0.05 M soln of electrolyte X is 1.0 x 10 –4 Scm-1 Calculate
(i) cell const. (ii) conductivity of 0.01 M Y soln.(iii) molar conductivity of 0.01M Y soln.
4. (a) State Kohlrausch law of independent migration of ions. How can the degree of dissociationof
acetic acid in a soln. to be calculated from its molar conductivity data.
(b) (i) Formulate the galvanic cell 2Cr + 3Fe2+  2Cr3+ + 3Fe
(ii) Calculate E0cell.
(iii) Calculate Ecell at 250C if [Cr3+] = 0.1M , [Fe2+] = 0.01 M
(E0Cr3+/Cr = -0.74V, E0Fe2+/Fe = -0.44V)
5. (a) Define molar conductivity of a solution and explain how molar
conductivity changes with change in concentration of a solution for a
weak and a strong electrolyte.
(b) A strip of nickel metal is placed in a 1 molar solution of Ni(NO3)2 and a strip of silver metal is
placed in a 1 molar solution of AgNO3.Anelectrochemical cell is created when the two
solutions are connected by a salt bridge and the two strips are connected by wires to volt meter.
(i)Write the balanced equation for the overall reaction occurring in the cell and calculate the
cell potential.
(ii) Calculate the cell potential, E at 250C for the cell, if the initial concentration of Ni(NO3)2
is 0.1 molar and the initial concentration of AgNO3 is 1 molar.
(E0 Ag+/Ag = +0.80V , E0 Ni2+/Ni = - 0.25V)
6. (a) Calculate the emf for the given cell at 250C.
Cr/Cr 3+ (0.1M)//Fe2+(0.01M)/Fe
0
(E Cr3+/Cr = -0.74V , E0 Fe2+ /Fe = -0.44 V)
(b) Calculate the strength of the current required to deposit 1.2 g of Mg from
molten MgCl2 in 1 hour.( 1F = 96500 C / mol , Mg = 24)
7. (a) Explain why electrolysis of aq. solution of NaCl gives H2 at cathode and Cl2 at anode.Write
overall reaction. ( E0 Na+/Na = - 2.71 V,E0 H2O/H2 = - 0.83 V, E0 Cl2/Cl- = + 1.36V,
E0 H+/H2/H2O = + 1.23V)
(b) The resistance of a conductivity cell containing 0.001 M KCl solution at 298K is 1500 Ω
Calculate the cell constant if conductivity of 0.001M KCl solution at 298 K is 0.146 x 10 -3 S/cm.
8. (a) Two electrolytic cells containing AgNO3 solution and dil. HCl solution
were connected in series A steady current of 2.5 A was passed through them till 1.078 g of
Ag was deposited. [Ag = 107.8 g/mol, 1F = 96500 C]
(i) How much electricity was consumed?
(ii) What was the weight of O2 gas liberated?
(b) Give reasons:
(i)
Rusting of iron pipe can be prevented by joining it with a piece of Mg
(ii) Conductivity of an electrolyte solution decreases with the decrease in concentration.
9. (a) Calculate the charge in Coulombs required for oxidation of 2 moles of water to oxygen.
(1 F = 96500 C/mol)
( b ) Zn/Hg oxide cell is used in hearing aids and electric watches.The following reactions occur
Zn(s)  Zn2+ + 2 e E0Zn2+/Zn = - 0.76V)
Hg2O+H2O + 2e-  2Hg + 2OHE0Hg+/Hg = - 0.344V)
Calculate :
(i) standard potential of the cell
(ii ) standard Gibbs’s energy
10. (a) State the relationship amongst cell const. of a cell, resistance of the soln. in the cell &
conductivity of soln. How is molar conductivity of a solute related to conductivity of its
solution..
(b) Calculate K for the reaction Fe+ Cd2+  Fe2+ + Cd
(E0Fe2+/Fe = -0.44V, E0Cd2+/Cd = -0.40V)
11. (a) Explain why electrolysis of an aq. Soln. of NaCl gives H2 at cathode & Cl2 at anode.
(E0Na+/Na = -2.71V, E0H2O/H2 = -0.83V, E0Cl2/2Cl- = +1.36V E02H+/1/2O2/H2O = +1.23V)
(b) The resistance of cond. Cell containing 0.001 M KCl soln. at 298 K is 1500 ohm What is the
cell const. if the conductivity of 0.001 M soln. at 298 K is 0.146 x 10 –3 S cm-1
12. (a) State Faraday's frst law of electrolysis. How much charge in terms of Faraday is
required for the reduction of 1 mol of Cu2+ to Cu.
(b) Calculate emf of the following cell at298K
Mg(s) | Mg2+(0.1 M) ll Cu2+ (0.01M) | Cu(s)
[Given E0cell = +2.71V, I F = 96500 C mol -1]
13. (a) In a cell reaction, the equilibrium constant K is less than one. Is E° for the cell
Positive or negative?
(b) What will be the value of K of E°cell = 0?
(c) What would happen if the protective tin coating over an iron bucket is broken in some
places ?
14. Shankar went to a shop to purchase a battery for their inverter. Shopkeeper showed them
two types of batteries, one with lead plates and the other with cadmium plates. The
battery with cadmium plates was more expensive than the lead battery. He decided to
purchase lead battery as it was cheaper. After reading the above passage, answer the
following questions:
(a)
As a student of chemistry, why would you suggest to Shankar to buy the
expensive cadmium plate battery. Give two reasons.
(b)
Which two values will you be promoting through your suggestions?
Chapter 4
(Chemical Kinetics)
5 marks
1 mark Questions
What is molecularity of the reaction Cl (g)  ½ Cl2(g)
Define the term order of reaction for chemical reaction.
List the factors which influence the rate of chemical reaction.
A reaction is second order w.r.t. A How is the rate of this reaction altered if the
concentration of A is (i) doubled (ii) reduced to half
5. How will you prove that a chemical reaction is of first order?
6. Define activation energy of a reaction.
7. Why does the rate of a reaction not remain constant throughout the reaction Process.
8. Derive the unit for first order rate constant.
9. Show that for a first order reaction,the time required for half life period is independent
of initial concentration.
10. Define rate of reaction.
11. Identify the order of reaction from the unit for rate constant L/mol/s.
12. Define elementary reaction.
13. For the reaction N2 + 3H2 2NH3 If ∆[NH3]/ ∆t = 4 x 10-8 mol/L/s what is the value of ∆[H2]/ ∆t
14. What are the units of rate constant for a pseudo first order reaction?
15. Give an example of a reaction where order and molecularity are same.
16. The decomposition reaction ofNH3 gas on Pt surface has a rate const.
K = 2.5x10-4 mol /L/sWhat is the order of reaction?
17. Distinguish between rate expression and rate constant of a reaction.
1.
2.
3.
4.
1. The reaction A+2B 2C+D
2, 3 Marks Questions
Expt.
[A]0
[B]0
Initial rate
2
0.6
0.3
0.384
0.6
0.768
1
3
4
0.3
0.3
0.6
0.3
0.6
(i)Derive the order of reaction w.r.t.both reactants [A] & [B]
(ii)Write the rate law.
0.96
0.192
(iii)Write the expression for the rate of reaction in terms of A & B.
2. Consider the reaction AP The change in concentration of A with time is shown
(i)Predict the order of reaction
(ii)Derive expression for the completion of the reaction
3. (a) 2N2O5  4NO2 + O2 is first order reaction with rate constant of 5x10-4 s-1.If initial
concentration of N2O5 is 0.25M. Calculate its
concentration after 2 min. Also calculate
half life for decomposition of
N2O5
(b)2A +B  3C The rate of appearance of C at time t is 1.3x10-4 mol/L/s
Calculate at this time (i)rate of reaction (ii) rate of disappearance of A
4. A first order decomposition reaction takes 40 min. for 30% decomposition Calculate its
t1/2 value.
5. What is meant by the rate const.’k’of a reaction. If the concentration be
expressed in mol/L units & time in sec.What would be the units for k
(i) for a zero order reaction (ii) for a first order reaction
6. (a) Derive the general form of the expression for the half life of a first order reaction
( b) The decomposition of NH3 on Pt surface is a zero order reaction What are the rates
of production of N2 & H2 if k = 2.5x10-4 mol/L/s
7. The half life for decay of radioactive C-14 is 5730 years An
archeological artifact containing wood has only 80% of C-14 activity is found in living
trees. Calculate the age of the artifact.
8. The rate of reaction increases to four times when the temp. is raised from 300K to320K
Calculate Ea of this reaction (R = 8.314J/mol/K)
9. Distinguish between order & molecularity of a reaction When could order &
molecularity of a reaction be the same.
10. The decomposition of PH3
4PH3  P4 + 6H2 has the rate law r = 6.0x10-4 s-1 & Ea is 3.05 x 105 J/mol
Calculate k at 310 K (R = 8.314J/mol/K)
11. For a chemical reaction what is the effect of catalyst on the following :
(i)
activation energy of the reaction
(ii)
rate constant of the reaction
12. For the reaction 2N2O5  4NO2 + O2 at 298 K
Sr. no.
[N2O5] mol/L
1
1.13 x10-2
3
0.62 x10-2
2
0.84 x10-2
Rate of disappearance of
N2O5(mol/L/min)
34 x 10-5
25 x 10-5
18 x 10-5
Determine (i) order of reaction (ii)rate constant (iii) rate law
13. Define (a) elementary step in a reaction
( b) rate of reaction
14. A first order reaction has a rate const. of 0.0051 min-1 If we begin with 0.10 M
concentration of reactant.What concentration of reactant will be left over after 3 hours?
15. For a decomposition reaction the values of rate const. k at two different temp. are given
below K1 = 2.15 x 10-8 L /mol/s at 650K ,K2= 2.39 x 10-7 L/mol/s at 700K Calculate Ea
for this reaction (R = 8.314J/mol/K)
16. (a) Explain the terms: (i) Order of reaction (ii) molecularity of a reaction
( b) The rate of reaction increases four times when the temperature changes from 300K to
320 K Calculate Ea ,assuming that it does not change with temperature . ( R =
8.314J/K/mol)
17. A reaction is of first order in reactant A and second order in reactant B.How is the rate of
this reaction affected when (i) [B] alone is increased to three times
(ii) [A] as well as [B] are doubled.
18. The rate constant for a reaction of zero order is 0.003mol/L/s.How long will it take for
the initial concentration of A to fall from 0.1M to 0.075M
19. Sucrose decomposes in acid solution into glucose and fructose according to the first
order rate law with t/2 = 3 hrs.Calculate the fraction of sucrose which remains after 8
hrs.
20. The rate constant of a reaction at 500K and 700K are 0.02 /s and 0.07 /s resp.Calculate
value of activation energy for the reaction (R = 8.314 J/mol/K)
21. Consider the decomposition of H2O2 in alkaline medium which is ctalysed by iodide ions.
2H2O2  2H2O + O2 This reaction takes place in two steps as given : Step I H2O2 +
I-  H2O + IO- Step II H2O2 + IO- H2O + I- +O2
(i)
Write the rate law expression and determine the order of reaction w.r.t. H2O2
(ii)What is the molecularity of each individual step.
22. In a hydrolysis reaction 5 g ethyl acetate is hydrolysed in presence of dil. HCl in 300
min. If the reaction is of 1st order and the initial concentration of ethyl acetate 22
mol/L,Calculate the rate const. of the reaction.
23. What do you understand by the rate law and the rate const. of a reaction?Identify the
order of reaction if the units of its rate const. are (i) mol/L/s (ii) L/mol/s
24. The thermal decomposition of HCOOH is first order reaction with a rate constant of
2.4x10 -3 /s at a certain temp. Calculate how long will it take for 3/4th of inititial quantity
of HCOOH to decompose. (log 0.25 = -0.6021)
25. A reaction is of second order with respect to a reactant.How is the rate of reaction
affected if the concentration of the reactant is reduced to half? What is the unit of rate
constant for such a reaction?
26. 2N2O5  4NO2 +O2 The first order reaction was allowed to proceed at 40 0C and the
data below were collected.
[N2O5] M
Time (min)
0.4
0
0.289
20
0.209
40
0.151
0.109
60
80
(a) Calculate the rate constant. Include units with your answer.
(b) What will be the concentration of N2O5 after 100 min.
(c) Calculate the initial rate of reaction.
27. (a) Distinguish between molecularity and order of reaction
(b )The activation energy for the reaction 2 HI  H2 + I2 is 209.5 kJ/mol at
581K.Calculate the fraction of molecules having energy equal to or greater than
activation energy (R= 8.31 J/mol/K)
28. The reaction N2 + O2 ↔ 2 NO contributes to air pollution whenever a fuel is burnt in
air at high temperature. At 1500 K, equilibrium constant K for it is 1.0x 10 -5 . Suppose in
a case [N2] = 0.80 mol/L and [O2] = 0.20 mol/L before any reaction occurs. Calculate the
equilibrium concentrations of the reactants and the product after the mixture has been
heated to 1500K.
29. For the reaction 2NO + Cl22NOCl
The following data were collected .All the measurements were taken at 263K
Expt no.
Initial [NO](M)
Initial [Cl2] (M)
1
0.15
0.15
3
0.30
0.15
2
4
0.15
0.25
0.30
0.25
Initial rate of
disappearance of Cl2
(M/min)
0.60
1.20
2.40
?
(i)
Write the expression for rate law.
(ii)
Calculate the value of rate constant and specify its units.
(iii) What is the initial rate of disappearance of Cl2 in expt.4?
30. (a) For a reaction A + B  P , the rate law is given by R = k [A]1/2[B]2
What is the order of this reaction?
( b ) A first order reaction is found to have a rate constant k=5.5 x 10 -14s-1 Find the half
life of the reaction.
31. The rate of reaction becomes four times when the temperature changes from293 K to 313
K.Calculatethe energy of activation (Ea) of thereaction assuming that it does not change
with temperature. [R = 8.314 J K -1, log4 = 0.6021]
32. Write units of rate constants for zero order and for the second order reactions if the
concentration is expressed in mol L–1 and time in second.
33. The rate constant for a first order reaction is 60 s–1. How much time will it take to reduce
the initial concentration of the reactant to its 1/10th value ?
5 marks Questions
1. )(i) Graph of log[Ro]/[R] t is given for first order reaction
(a) What is the relation between slope of this line & rate const.
(b) Calculate the rate const. Of the above reaction if the slope is2x10-4 s-1
(ii) Derive the relation between half life of a first order reaction & its rate constant.
2. For a chemical reaction variation in the [R]  t (first order graph ln log [R]  t )
(a) What is the order of reaction
(b) What are the units of rate constant k
(c) Give the relationship between k & t ½
(d) What does the slope of the above line indicate?
(e) Draw a plot log [R0]/[R]  t
3. (a) Explain the terms: (i) Rate of reaction (ii) Activation energy of a reaction
(b) The decomposition of PH3 proceeds according to the following equation :
4PH3  P4 + 6H2 It is found that the reaction follows the following rate equation
Rate = k [PH3] The half life of PH3 is 39.9 s at120 0C
(i)
How much time is required for 3/4th of PH3 to decompose?
(ii)
What fraction of the original sample of PH3 remain behind after one minute.
4. (a) For the reaction:
C12H22O11 + H2O  C6H12O6 + C6H12O6
Write (i) Rate of reaction expression ( ii) Rate law equation ( iii) molecularity
( iv) order of reaction
( b) The following data were obtained during the first order thermal decomposition of SO2Cl2 at
const. volume.
(iii)
SO2Cl2 (g)  SO2(g) + Cl2(g)
experiment
Time (s)
Total press. (atm)
2
100
0.6
1
0
0.5
Calculate the rate of reaction when total pressure is 0.65 atm.
5. (a) Illustrate graphically the effect of catalyst on activation energy
( b ) Catalysts have no effect on equilibrium const. why?
( c) The decomposition of A into product has value of K as 4.5 x 10 3 /s at 10 0 C and
activation energy is 60 KJ/mol.Calculate the temp. at which the value of K be 1.5 x 10 4
/s
6. (a) Explain difference between the average rate and instantaneous rate of Reaction.
(b ) In pseudo first order hydrolysis of ester in water, the following results are obtained.
T in seconds
[Ester] M
0
30
0.55
60
0.31
0.17
90
0.085
(i) Calculate the average rate of reaction between time intervals 30 to 60 seconds
(ii) Calculate the pseudo first order rate constant for the hydrolysis of ester.
7. Consider the reaction
2A + B  C+ D
Following results were obtained in
experiments designed to study the rate of reaction .
Expt. No.
1
2
3
Initial concentration (mol/L)
Initial rate of
formation
[A]
[B]
[D] (M/min)
0.2
0.2
3.0 x 10-3
0.1
0.2
0.1
0.4
1.5 x 10 -3
6.0 x 10 -3
(a) Write the rate law for the reaction
(b) Calculate the value of rate constant for the reaction.
(c) Which of the following possible reaction mechanism is consistent with the rate law found
in (a)?
(i)
(ii)
A + B  C + E (slow)
A + E  D (fast)
B  C + E (slow)
A + E  F (fast)
A + F  D (fast)
8. For the hydrolysis of methyl acetate in aqueous solution, the following results were
obtained : t/s : 0 ,30 ,60 [CH3COOCH3]/mol L-1 : 0.60, 0.30, 0.15
(i) Show that it follows pseudo first order reaction, as the concentration of water remains
constant.
(ii) Calculate the average rate of reaction between the time interval 30 to 60 seconds.
9. For a reaction A + B → P, the rate is given by
Rate = k [A]2[B]
(i) How is the rate of reaction affected if the concentration of A is doubled ?
(ii) What is the overall order of reaction if B is present in large excess ?
(b) A first order reaction takes 23.1 minutes for 50% completion. Calculate the time
required for 75% completion of this reaction. (Given : log 2 = 0.301, log 3 = 0.4771,
log 4 = 0.6021)
10. For a reaction A + B → P, the rate is given by Rate = k[A] [B]2
(i) How is the rate of reaction affected if the concentration of B is doubled ?
(ii) What is the overall order of reaction if A is present in large excess ?
(b) A first order reaction takes 30 minutes for 50% completion. Calculate the time
required for 90% completion of this reaction. (log 2 = 0.3010)
Chapter : 5
(Surface Chemistry)
1 Mark Questions
4 marks
1. Why is FeCl3 preferred over KCl in case of cut leading to bleeding?
2. What are the physical states of dispersed phase & dispersion medium of froth?
3. What causes Brownian movement in a colloidal solution?
4. Which has a higher enthalpy of adsorption, physisorption or chemisorption?
5. Define electrophoresis briefly.
6. Why does physisorption decrease with increase in temp.?
7. In chemisorption why x/m initially increases& then decreases with rise in temperature?
8. What is the coagulation process?
9. Define the term Tyndall effect.
10. Write three special features of chemisorption which are not found in physisorption.
11. Name two types of adsorption phenomenon.
12. What are emulsions? State one application of emulsification.
13. What is meant by shape selective catalysis?
14. Give an example of shape selective catalyst.
15. Which of the following is most effective electrolyte in coagulation of Fe2O3.H2O/Fe3+ sol
: KCl,AlCl3,MgCl2,K4[Fe(CN)6]
16. What is lyophobic colloid? Give one example for them.
17. What is the sign of ∆H and ∆S when gas is adsorbed by adsorbent?
18. What is the difference between adsorption and absorption ?
19. Distinguish between physisorption and chemisorptions.
20. Why is adsorption always exothermic?
21. Of physisorption or chemisorption , which has a higher enthalpy of formation?
22. what is especially observed when a beam of light is passed through colloidal solution?
23. Out of BaCl2 and KCl, which one is more effective in causing coagulation of a negatively
charged colloidal Sol ? Give reason.
24. Give one example each of 'oil in water' and 'water in oil' emulsion.
25. Out of AlCl3 and NaCl, which is more effective in causing coagulation of a negative sol
and why ?
26. What is the effect of temperature on adsorption ?
27. How does adsorption of a gas on a solid surface vary with increase in Pressure?
28. What is the sign of ∆H & ∆S when a gas is adsorbed by an adsorbent?
29. Name the type of potential difference produced between the fixed charged layer and and
diffused layer having opposite charges around the colloidal particles.
2, 3 Marks Questions
1. Consider the adsorption isotherm given & interpret the variation in the extent of
adsorption (x/m) when (a) (i) temp.increases at constant pressure ( ii) pressure increases
at constant temp. (b) Name the catalyst & promoter used in Haber’s process for
manufacture of NH3.
2. Explain: (a) Fe(OH)3 sol gets coagulated on addition of NaCl solution
(b) Cottrell’s smoke precipitator is fitted at the mouth of the chimney used in factories
(c ) Physical adsorption is multi layered while chemisorption is monolayered
3. (a) Adsorption of a gas on the surface of solid is generally accompanied by a decrease in
entropy. Still it is a spontaneous process.Explain.
( b) How does an increase in temp. affect both physical as well as chemical adsorption
4. What are lyophilic & lyophobic sols? Give one example of each type which one of these
two types of sols is easily coagulated & why?
5. What is observed when (i) an electrolye KCl is added to hydrated ferric oxide sol. (ii)an
electric current is passed through a colloidal solution
(iii)a beam of strong light is passed through a colloidal solution
6. Differntiate between multimolecular & macromolecular colloids? Give one example of
each. How are these two types of colloids different from associated colloids.
7. What is observed when:- (i) a beam of light is passed through colloidal Solution (ii)An
elctrolyte NaCl is added to hydrated Fe2O3 sol
(iii)An electric current is passed through a colloidal solution
8. (a)What is the difference between a colloidal solution & an emulsion? Give one example
of each (b) What are emulsifiers?
9. Explain with example: (a) Peptization (ii) gel (iii) dialysis
10. Distinguish between homogeneous & heterogeneous catalysis? What role does adsorption
play in heterogeneous catalysis?
11. Distinguish between micelles & colloidal particles. Give one example of each.
12. How are the following colloids different from each other with respect of
dispersion
medium & dispersed phase?Give one example of each type:(i) an aerosol (ii) a hydrosol (iii) an emulsion
13. What is the difference between a colloidal solution & emulsion? What is the role of
emulsifier in forming emulsion?
14. Describe the following: (i) Tyndall effect (ii) Shape selective catalysis
15. What is meant by coagulation of a colloidal solution? Name any method by which the
coagulation of lyophobic sol can be carried out.
16. Define the following terms:(i) Peptization (ii) Reversible sol
17. Give reasons for the following observations:
(a) Peptizing agent is added to convert ppt into colloidal solution
(b) Cottrell’s smoke precipitator is fitted at the mouth of chimney used in factories
(c) Colloidal gold is used for intramuscular injection
18. (a) Heat of adsorption is greater for chemisorption than physisorption why?
( b) What is colloidion ?
( c) Differentiate between peptization and coagulation.
19. (a) Give main difference between lyophilic and lyophobic colloids.
(b) Explain (i) sky appears blue in colour (ii) A freshly formed ppt of Fe(OH)3 can be
converted to a colloidal sol by shaking it with a small quantity of FeCl3.
20. Classify colloids where the dispersion medium is water.State their characteristics and
write an example of each of these classes.
21. Explain how the phenomenon of adsorption finds application in each of the Following:
(a) Production of vacuum
(b) Heterogeneous catalysis
(c) Froth floatation process
22. Define each of the following
(i)
Micelles
(ii)
Peptization
(iii) Desorption
23. What is an adsorption isotherm? Describe Freundlich adsorption isotherm.
24. Discuss the effect of pressure and temperature on adsorption of gases on solids.Describe
the application adsorption in controlling humidity.
25. Explain the following terms giving suitable example for each:
a) Aerosol (b) Emulsion (c) Micelle
26. Name the two groups into which phenomenon of catalysis can be divided. Give an
example of each group with the chemical equation involved.
27. What is meant by coagulation of a colloidal solution? Describe briefly any three methods
by which coagulation of lyophobic sols can be carried out.
28. Describe a conspicuous change observed when :
(a) A solution of NaCl is added to a sol of hydrated ferric oxide.
(b) A beam of light is passed through a solution of NaCl and then through a sol
29. Define the following terms giving one suitable example for each:
(a) Electrophoresis
(b) Micelles
(c) Peptization
30. Differentiate among a homogeneous solution, a suspension and a colloidal solution,
giving a suitable example of each.
31. Present a classification of colloids where dispersion medium is water.State the
chatacteristics and one example of each of these classes.
32. What are the characteristics of the following colloids? Give one example of each.
(a) Multimolecular colloids
(b) Lyophobic sols
(c) Emulsions
33. Give reasons for the following : (a) Some substances can act both as colloids and
crystalloids. (b) Artificial rain is caused by spraying salt over clouds.
(c) Deltas are formed when river meets sea water.
34. Give reasons for the following observations :
(i)
Leather gets hardened after tanning.
(ii)
Lyophilic sol is more stable than lyophobic sol.
(iii)
It is necessary to remove CO when ammonia is prepared by Haber’s process.
35. (a) In reference to Freundlich adsorption isotherm write the expression for adsorption of
gases on solids in the form of an equation.
(b)Write an important characteristic of lyophilic sols.
(c) Based on type of particles of dispersed phase, give one example each of associated
colloid and multimolecular colloid.
36. Define adsorption with an example. Why is adsorption exothermic in nature ? Write the
types of adsorption based on the nature of forces between adsorbate and adsorbent.
37. Explain what is observed when
(i)
Silver nitrate solution is added to potassium iodide solution.
(ii)
The size of the finest gold sol particles increases in the gold sol.
(iii)
Two oppositely charged sols are mixed in almost equal proportions.
Chapter 6
(General Principles & Processes of Isolation of Elements)
(3 marks)
1.
2.
3.
4.
1 mark questions
What is the role of coolectors in the froth floatation process for the concentration of ores?
Differentiate between a mineral and an ore.
Why is that only sulphide ores are concentrated by Froth floatation process?
Name the depressant which is used to separate ZnS and PbS ores in Froth floatation
process.
5. Name the method that is used for refining of nickel.
6. Name the method that is used for refining of copper metal.
7. Which reducing agent is employed to get copper from the leached low grade copper ore?
8. What is the role of flux in metallurgical processes?
9. Define slag.
10. What is gangue?
11. What type of ores can be concentrated by the magnetic separation method?
12. What is meant by the term Pyrometallurgy.
13. What is leaching?
14. Differentiate between cast iron and wrought iron.
15. What is copper matte?
2, 3 Marks Questions
1. Account for (a) the reduction of metalic oxide is easier if the metal formed is in liquid
state at the temp. of reduction.
(b)the reduction of Cr2O3 with Al is thermodynamically feasible,yet it does not occur at
room temp.
(c) Pine oil is used in froth floatation method
2. ∆G for MgO & CO at 1273K & 2273K are given ∆G [MgO] = -941KJ/mol at 1273K &
∆G [CO]= - 439KJ/mol,
∆G [MgO] = -314 KJ/mol at 2273K & ∆G [CO]= - 628 KJ/mol
Predict the temp. at which C can be used as a reducing agent for MgO.
3. (a) Name the method used for refining of (i) Ni (ii) Zr
(b) The extraction of gold by leaching with NaCN involves both Oxidation &
Reduction. Justify giving equation.
4. State briefly the principles which serves as basis for the following operations in
metallurgy
(i)Froth floatation process (ii)Zone refining (iii )Refining by liquation
5. A) Explain the basic principles
(i)Vapour phase reefing (ii) Electrolytic refining
6. State briefly the following giving one example for each :
(a) Calcination(b)Roasting
7. Answer the following :
(i) What is the role of cryolite in the metallurgy of aluminium ?
(ii) Differentiate between roasting and calcination.
(iii) What is meant by the term ‘chromatography’ ?
8. Write the reactions taking place in different zones of the blast furnace to obtain Iron.
9. (i) Indicate the principle behind the method used for the refining of zinc.
(ii) What is the role of silica in the extraction of copper ?
(iii) Which form of the iron is the purest form of commercial iron ?
10. Outline the principles behind the refining of metals by the following methods :
(i)
Zone refining method (ii) Chromatographicmethod
11. (i) Name the method used for the refining of titanium.
(ii)
What is the role of Zn in the extraction of silver ?
(iii) Reduction of metal oxide to metal becomes easier if the metal obtained is in liquid
state. Why ?
12. State briefly the principles involved in the following operations in metallurgy. Give an
example. (i) Hydraulic washing. (ii) Zone refining.
13. Describe the principle controlling each of the following processes
(i) Preparation of cast iron from pig iron
(ii) preparation of pure alumina from bauxite ore.
14. Describe the principle controlling each of the following processes
(i) Vapour phase refining of Ti metal
(ii) Froth floatation method of concentration of a sulphide ore
15. Describe the role of following: (i) NaCN in the extraction of Ag from silver ore.
(ii) I2 in the refining of Ti. (iii) Cryolite in the metallurgy of Al
16. What chemical principle is involved in choosing a Reducing Agent for getting the metal
from its oxide ore? Consider the metallic oxide,Al2O3 & Fe2O3 & Justify the choice of
Reducing Agent in each case.
17. How is copper extracted from a low grade ore of it?
18. (i) Write the reaction involved in the extraction of silver after the silver ore has been
leached with NaCN.
(ii)Name one chief ore each of copper and aluminium. Name the method used
for the concentration of these two ores.
19. Give Reasons:
(a) Alumina is dissolved in cryolite for electrolysis instead of being electrolysed directly
(b) ZnO can be reduced to metal by heating with carbon but not Cr2O3
(c) Extraction of Cu directly from sulphide ore is less favourable than that from its oxide
ore through reduction .
20.
(a) Name the method used for removing gangue from sulphide ores.
( b) How is wrought iron different from steel?
Chapter : 7 (The p-Block Elements)
8 marks
1 Mark Questions
1. Write equation Complete hydrolysis of XeF6.
2. Predict the shape of ClF3 on the basis of VSEPR theory
3. In the ring test for identification of NO3- ion what is the formula of the compound
responsible for the brown ring formed at the interface of two liquids.
4. In which one of the two structures NO2+ & NO2-, the bond angle has a higher value?
5. Why is the bond angle in PH3 molecule lesser than that in NH3 molecule?
6. Which is a stronger acid in aq. Soln. of HF or HCl ?
7. Which is stronger acid in aq.soln. HCl or HI?
8. N does not form any pentahalide like P why?
9. Why is N2 very unreactive as compared to P4
10. When HCl reacts with finely powdered iron it forms FeCl2 & not FeCl3 why?
11. F exhibits only –1 oxidation state in its compound whereas other halogens exhibit many other
oxidation state why?
12. Why are halogens mostly coloured?
13. Why is red P less reactive than white P?
14. Write the formula & structure of noble gas species which are iso structural with ICl4- & BrO315. F does not exhibit any + ve oxidation state Why?
16. Why does NO2 dimerise?
17. What is O.N. of P in H3PO2 molecule?
18. Draw structure of O3 molecule.
19. Which Xe compound is isostructural with ICl4- ?
20. Which of the following compounds has a lone pair of electron at the central atom?
H2S2O8,H2S2O7,H2SO3,H2SO4
21. Draw the structure of XeF2 molecule.
22. Draw the structure of XeF4 molecule.
23. Draw the structure of BrF3 molecule.
24. What is the covalence of nitrogen in N2O5?
25. Why are the two S –O bonds in SO2 molecule of equal strength?
26. Why are pentahalides of metals more covalent than its trihalides?
27. Why is BiH3 the strongest reducing agent amongst the hydrides of group 15 elements?
28. Which is stronger reducing agent , SbH3 or BiH3 and why?
29. What is the basicity of H3PO2 acid and why?
30. Which one of PCl4 + and PCl4 – is not likely to exist and why?
31. Although the H –bonding in HF is much stronger than that in water,yet water has a much
higher b.p. than HF. Why?
32. Which is more acidic and why,H2O or H2S?
33. Name two poisonous gases which can be prepared from chlorine gas.
34. Which aerosol depletes ozone layer?
35. What is the basicity of H3PO3 and why?
2, 3 Marks Questions
1. Draw the structures of the following molecules:
(i)
XeOF4
(ii)
H3PO3
2. Account for the following:
(i)
Among the halogens F2 is the strongest O.A.
(ii)
F exhibit only –1 oxidation state whereas other halogens exhibit higher positive
oxidation state also
(iii) Acidity of oxo acids of Cl is HOCl<HOClO<HOClO2<HOClO3
3. Give reasons: (a) CN- ion is known but CP- is not
(b) NO2 dimerises to form N2O4
(c) ICl is more reactive than I2
Account
for
(a) Cl2 water has both oxidizing & bleaching properties
4.
(b)H3PO2 &H3PO3 act as good R.A.while H3PO4 does not
(c)On oxidation of O3 gas to KI soln. violet vapours are obtained.
5. (a) What is the covalence of nitrogen in N2O5
(b) Explain why both N & Bi do not form pentahalides while P does.
6. When conc. H2SO4 was added into an unknown salt present in a Test tube, a brown gas A was
evolved. This gas intensified when Cu turnings were also added into this T.T. On cooling the
gas A changed into a colourless gas B
(i) Identify the gases A& B
(ii) Write the equations for the reactions involved.
7. (a) Why does Cl2 water lose its yellow colour on standing
(b)What happens when Cl2 water reacts with cold dil soln. of NaOH. Write equation only.
8. Write down the equations for hydrolysis of XeF4 & XeF6.Which of these two reactions is a
redox reaction.
9. Reasons: (i) NH3 is stronger base than PH3 (ii) S in vapour state exhibits a paramagnetic
behavior
10. Draw structures of (i) SF4 (ii) XeF4
11. Write equations (i) Cl2 reacts with hot conc. soln. of NaOH
(ii)orthophosphorous acid is heated
(iii)PtF6 & Xe are mixed together
12. (i) which neutral molecule would be isoelectronic with ClO(ii)Of Bi (V) & Sb(V) which may be stronger Oxidizing agent & why?
13. Reasons (i) P shows marked tendency for catenation but N shows little
tendency for catenation
( ii )The electron gain enthalpy with –ve sign for O (-141 KJ/mol) is less
than that for S(-200KJ/mol)
14. Draw structures of (i) H2S2O7(ii) NO315. Draw the structures of (i) HClO4 (ii)BrF3 (iii) XeF4
16. Reasons: (i) O2 molecule has formula O2 while S has S8
(ii) H2S is less acidic than H2Te
17. (a) Arrange HClO,HClO2,HClO3,HClO4 in order of acidic strength. Give reason.
(b)Write equation for Cl2 water reacts with conc. soln. of NaOH Justify that
this is a disproportionation reaction.
(c) Give one use of ClF3
18. (a) Why do some noble gases form compounds with F & O only.
(b) How are the following compounds prepared from XeF6 (i) XeOF4 (ii)XeO3
(c) Draw structure of BrF3
19. (a) How are interhalogen compounds formulated & how are they prepared?
(b) which neutral molecule would be isoelectronic with ClO- ?
20. (a) How does Xe atom forms compounds even though the Xe atom has a
closed shell electronic configuration
(b) Draw structures of XeOF4
(c) Complete XeF4 + H2O
21. (i) Draw structure of SO2 molecule .Comment on the nature of two S-O bonds formed in it
are the two S-O bonds in this molecule equal?
(ii) What happens when white P is heated with conc. NaOH soln.in an inert gas atmosphere.
22. (i) Why is BiH3 the strongest R.A. among all the hydrides of gr 15 elements.
(ii) H2O is liquid while H2S is a gas why?
(iii) Why is Ka2<<Ka1 for H2SO4 in water
23. Complete (i) XeF2 + H2O (ii) PH3 + HgCl2 
24. (i)Why is Bi(V) stronger O.A. than Sb(V)
(ii)Complete : P4 + NaOH + H2O 
O3 + I- + H2O
(iii)Draw structure of XeF4 , BrF3
25. Explain :
(i)
F does not exhibit any +ve oxidation state
(ii)
The majority of known noble gas compounds are those of Xe
(iii) P is much more reactive than N
26. Reason (i) PH3 is weaker base than NH3
(ii)OF6 copound is not known
(iii)F provides the largest variety of interhalogen compounds amongst the halogen
27. Write equation: (i) Cl2 + NaOH (hot & conc.)
(ii)XeF6 + H2O 
(iii) NaOH +SO2(excess)
28. Give reasons: (i) N2 is not particularly reactive
(i)
Halogens are strong O.A.
(ii)
SF6 is less reactive than SF4.
29. Complete (i) I2 + HNO3 (conc) 
(ii) HgCl2 + PH3 
30. Draw structures of (i) H4P2O5 (ii) XeF4
31. Account for the following:
(i) NCl3 is an endothermic compound while NF3 is an exothermic one
(ii) XeF2 is a linear molecule without a bend.
(iii)The electron gain enthalpy with – ve sign of F is less than that of Cl still F2 is strong O.A.
than Cl2.
32. Complete (i) NaOH (cold & dil.) + Cl2 
(ii) XeF6 + H2O (excess) 
33. Account for the following:
(i)
The electron gain enthalpy with – ve sign is less for O than that of S.
(ii)
P shows greater tendency for catenation than N
(iii) F never acts as a central atom in polyatomic interhalogen compounds.
34. Draw the structure of white and red phosphorous.Which one of these two types of
phosphorous is more reactive and why?
35. Draw structures of O3 and S8 molecules.
36. Draw structures of XeOF4 and HClO4 molecules.
37. Give reasons for the following:
(i)
Oxygen is a gas but sulphur is a solid
(ii)
O3 acts as a powerful oxidizing agent
(iii) BiH3 is the strongest reducing agent amongstall the hydrides of group 15 elements.
36. give reasons for the following:
(i)
Though nitrogen exhibits +5 oxidation state, it does not form pentahalide.
(ii)
Electron gain enthalpy with negative sign of fluorine is less than that of chlorine.
(iii) The two oxygen-oxygen bond length in ozone molecule are identical.
37. (i) Draw structure of phosphinic acid(H3PO2)
(ii) Write a chemical reaction for its use as a reducing agent.
38. (a)Suggest a quantitative method for estimation of gas which protect us from uv rays of the
sun
(b)Nitrogen oxides emitted from the exhaust system of supersonic jet aeroplanes slowly
deplete the concentration of O3 layer in the upper atmosphere.Comment.
39. Write equation for the following reaction
( a) thermal decomposition of (NH4)2Cr2O7
( b) reactionof Cl2 with cold and hot dil.NaOH
( c) when phosphine is passed through HgCl2 solution
40. Give chemical reaction in support of the following observations
( a) H2SO4 has low volatility.
( b) I- can be oxidized by O2 in acidic medium
41. Complete the following:
(a) (NH4)2Cr2O7 on heat 
(b) I- + O3 +H2O 
42. Draw the structures (a) H2S2O8 (b)XeO3 ( c) HOClO2
43. Give reasons:
(a) Interhalogen compounds are more reactive thn halogens
(b) PCl5 is known but NCl5 is not known.
(c) Among all the noble gases only Xe is known to form compounds with O and F
44. How would you account for the following:
(i) H2S is more acidic than H2O.
(ii) The N-O bond in NO2– is shorter than N-O bond in NO3(iii) Both O2 and F2 stabilize high oxidation states but the ability of O2 to
stabilize the higher oxidation state exceeds that of F2
45. Account for the following:
(i) NF3 is an exothermic compound but NCl3 is not
(ii)The acidic strength of compounds increasesin the order PH3 < H2S< HCl
(iii)SF6 is kinetically inert.
46. Complete the following chemical equations:
(i)
NaOH (hot and conc.)+ Cl2 
(ii)
XeF4 + O2F2 at 143 K 
(iii) Br2 + F2 (excess) 
47. (a) Mention the optimum conditions for the industrial manufacture of ammonia by Haber’s
process.
(b) Explain the following giving appropriate reasons:
(i)sulphur vapour exhibits paramagnetic behavior.
(ii) red phosphorus is less reactive than white phosphorus.
48. Suggest the possible reason for the following observations:
(i)In the solid state , PCl5 behaves as an ionic species.
(ii)H2S is more acidic than water
(iii)Fluorine forms the largest number of interhalogen compounds amongst the halogens.
49. Complete the following chemical equations:
(i)
NH4Cl + NaNO2 
(ii)
P4 + NaOH + H2O 
(iii) Xe + F2 (at 673K,1bar)
50. Complete the following chemical equations:
(i)
HgCl2 + PH3 
(ii)
NaOH + Cl2 
(hot and conc.)
(iii) XeF4 + O2F2 
51. Complete the following chemical equations:
(i)Sn + 2PCl5 (heat) 
(ii)Fe3+ + SO2 +H2O 
(iii)XeF2 + H2O 
52. Give reasons for the following:
(i)Where R is an alkyl group,R3P = O exist but R3N=O does not
(ii)PbCl4 is more covalent than PbCl2
53. Explain the following :
(i) Nitrogen is much less reactive than phosphorus.
(ii) NF3 is an exothermic compound but NCl3 is an endothermic compound.
5 marks Questions
1. A translucent white waxy solid A on heating in an inert atmosphere is converted to its
allotrope B. Allotrope A on reaction with very dil KOH liberates a highly poisonous gas
C having rotten fish smell. With excess of Cl2 forms D which hydrolyses to compound
E Identify A to E.
2. Conc. H2SO4 is added to following chemicals in a test tube Identify the change observed
& support your answer with equation
(i)cane sugar(ii)NaBr(iii) Cu-pieces(iv) S powder (v) KCl
3. An element X exists as yellow solid in standard state It forms a volatilehydride B which is
a foul smelling gas & is extensively used in qualitative analysis of salts when treated with
oxygen B forms an oxide C which is pungent smelling gas. This gas is passed through
acidified KMnO4 soln. decolourises it. C gets oxidized to another oxide D in the presence
of heterogeneous catalyst. Identify A,B,C,D & also give chem. reaction of C with
acidified KMnO4 soln. & for conversion of C to D.
4. Complete the equation: (i) Ca3P2 + H2O 
(ii) Cu2+ + NH3 (aq) (excess) 
(iii) F2 (g) + H2O (l) 
(iv)XeF4 + H2O
(v)O3 + I- + H2O
5. Reasons: (i) S in vapour state exhibits a paramagnetic behaviour
(ii) NH3 has greater affinity for protons than PH3
(iii) The –ve value of electron gain enthalpy of F is less than that of Cl
(iv)SF6 is much less reactive than SF4
(v)Of the noble gases only Xe is known to form well established chemical
compounds.
6. (a) Describe the favourable conditions for the manufacture of
(i) NH3 by Haber’s process
(ii) H2SO4 by Contact process
(b) Draw the structures of (i) PCl5 (ii) S8 (iii) ClF3
7. (a)Reasons: (i) P4 is more reactive than N2
(ii) All bonds in PCl5 are not equal in length.
(iii) S in vapour state exhibits a paramagnetic behaviour
(b) Draw the structures of (i) BrF3 (ii) XeF2
8. (a) Draw structures of (i) H2S2O8(ii) HClO4
(b) How would you account for the following :
(i) NH3 is stronger base than PH3
(ii) F2 is a stronger O.A. than Cl2
(iii)S shows greater tendency for catenation than O.
9. (a)Draw structures of (i) H2S2O7(ii) HClO3
(b) How would you account for the following :
(i)
In the structure of HNO3 the N-O bond (121pm) is shorter than N-OH bond (140pm)
(ii)
All P-Cl bonds in PCl5 are not equivalent.
(iii) ICl is more reactive than I2
10. (a)Draw structures of (i) H3PO2(ii) BrF3
(b) How would you account for the following :
(i)
No chemical compound of He is known
(ii)
Bond dissociation energy of F2 is less than that of Cl2
(iii) P shows greater tendency for catenation than N.
11. (a)Draw structures of (i) H4P2O7(ii) XeF4
(b) How would you account for the following :
(i) The –ve value of electron gain enthalpy is less for F than that for Cl
(ii) F2 is a stronger O.A. than Cl2
(iii) HF has a much higher b.p. than HCl
12. Reasons:
(i) NH3 is stronger base than PH3
(ii) S shows greater tendency for catenation than O.
(iii) Bond dissociation energy of F2 is less than that of Cl2
(iv) In the structure of HNO3 the N-O bond (121pm) is shorter than N-OH bond (140pm)
(v) SF4 is easily hydrolysed wheras SF6 is not
13. (a) Complete (i) XeF2 + PF5 
(ii)Cl2 + NaOH (hot& conc.) 
(b) Explain (i) S in vap. State exhibit paramagnetism
(ii)+3 oxidation state becomes more & more stable from As to Bi in the group
(iii) XeF2 has a linear sructure & not a bent angular structure
14. Complete (i)PCl5 + H2O (excess) 
(ii) F2 + H2O 
Reasons: (i) No chemical compound of He is known
(ii)In soln of H2SO4 in water Ka2 is less than Ka1
(iii)P shows greater tendency for catenation than N.
15. Complete (i) SO2 + MnO4- + H2O 
(ii) HgCl2+ PH3
Explain (i) S shows greater tendency for catenation than O.
(ii) F is stronger O.A. than Cl
(iii)The + 5 oxidation state becomes less stable down the group in gr.15 of
the Periodic Table.
16. (i) Complete (a) : P4 + NaOH + H2O 
(b) Cu + HNO3 (dil) 
(ii) Explain
(a) H2O is liquid while H2S is a gas
(b) Fe dissolves in HCl to form FeCl2 & not FeCl3
(c) He is used in diving equipments
17. Reason : (i)In the solid state PCl5 behaves as an ionic species
(ii) H2S is more acidic than water
(iii)N2 is not particularly reactive
(iv)Halogens are stronger O.A.
(v)SF6 is less reactive than SF4
(vi )F forms largest no. of interhalogen compounds amongst halogens.
18. (a) Complete the following:
1. NaOH (hot and conc.) + Cl2 
2. XeF6 + H2O
( b ) How would you account for the following:
( i ) The value of EGE with –ve sign of S is higher than that of O
( ii ) NF3 is exothermic but NCl3 is endothermic.
( iii ) ClF3 molecule has T shaped structure and not a triangular planar one.
19. (a) Complete the following:
(i) P4 + SOCl2  (ii) XeF4 + H2O
(b) Explain the following giving reason
(i) The stability of +5 oxidation state decreases down the group in gr. 15 of the P.T.
(ii) Solid PCl5 behaves as an ionic compound.
(iii) Halogens are strong oxidizing agent.
20. (a) Complete (i) HgCl2 +PH3  (ii) SiO2 + HF
(b) Explain (i) S in vapour state exhibit paramagnetic behavior
(ii) The stability of +3 state increasesdown the gr.in gr. 15 of the P.T.
(iii) XeF2 has a linear shape and not a bent structure
21. (a) Complete (i) AgCl + NH3 (ii) P4 + NaOH + H2O 
(b) Explain (i)H2S is less acidic thanH2Te
(ii) F2 is stronger O.A. thanCl2
(iii) Noble gases are least reactive elements.
22. (a) An orange solid A on heating gives a colourless gas B. The gas B in dry
condition is passed over heated Ca to give a solid C. The solid C further
reacts with water to produce a gas D which forms a blue coloured
compound E on reaction with CuSO4 solution. Identify A,B,C,D,E and
give the sequence of reactions involved.
( b) Arrange the following in order of property indicated for each set
(i) HCl, HI, H Br, HF (decreasing thermal stability)
(ii) Xe, He, Kr, Rn, Ne (decreasing order of EGE)
23. (a) Give reasons:
(i) solid PCl5 is an ionic compound.
(ii) Most of the reactions of F are exothermic.
(iii) O3 is thermodynamically unstable.
(b) Draw the structure of the following.
( i) XeOF2 ( ii) H4P2O7
24. ( a) Draw the structures of the following molecules.
(i)
(HPO3)3
( ii) BrF3
( b) Complete the following equations
(i)
HgCl2 + PH3 
(ii)
SO3 + H2SO4 
(iii)
XeF4 + H2O 
25. ( a)
(i) Cl2 gas is passed through a hot concentrated solution of NaOH
(ii ) SO2 gas is passed through an aqueous solution of a Fe 3+ salt
( b) Answer thefollowing:
(i)
What is the basicity of H3PO3 and why?
(ii)
Why does F not play the role of central atom in interhalogen compounds
(iii)
Why do noble gases have very low b.p.?
26. ) (a) Explain
(i)
NF3 is an exothermic compound whereas NCl3 is not
(ii)
F2 is more reactive of all the four common halogens
(b ) Complete
(i)
C + conc. H2SO4 
(ii)
P4 + NaOH + H2O 
(iii) Cl2 + F2(excess) 
27. (a) Account for the following:
(i)
The acidic strength decreases in the order HCl>H2S>PH3
(ii)
Tendency to form pentahalides decreases down the group in group 15 of the periodic
table
(b) Complete the following equations:
(i) P4 + SO2Cl2 
(ii) XeF2 + H2O 
(iii) I2 + HNO3 (conc.) 
28.(i) Cu + HNO3 (dilute) 
(ii)XeF4 + O2F2 
(b) explain the following observations:
(i) phosphorus has a greater tendency for catenation than nitrogen.
(ii) oxygen is a gas but sulphur is a solid
(iii)The halogens are coloured. Why?
29. (a) Complete the following chemical reaction equations:
(i)
P4 + SO2Cl2 
(ii)
XeF6 + H2O 
(b) Predict the shape and angle(900 or more or less) in each of the following cases:
(i) SO32- and the angle O-S-O
(ii) ClF3 and the angle F-Cl-F
(iii) XeF2 and the angle F- Xe –F
30. (a) Draw molecular structures of following compounds:
(i)
XeF6
(ii)
H2S2O8
(b) Explain the following observations:
(i) The molecules NH3 and NF3 have dipole moments which are of opposite direction.
(ii) All the bonds in PCl5 molecules are not equivalent.
(iii) S in vapour state exhibits paramagnetism.
31.(i) Which allotrope of phosphorus is more reactive and why ?
(ii) How the supersonic jet aeroplanes are responsible for the depletion of ozone layers ?
(iii) F2 has lower bond dissociation enthalpy than Cl2. Why ?
(iv) Which noble gas is used in filling balloons for meteorological observations ?
(iv)
Complete the equation : XeF2 + PF5 →
32. (i)Which poisonous gas is evolved when white phosphorus is heated with conc. NaOH
solution ? Write the chemical equation.
(b) Write the formula of first noble gas compound prepared by N. Bartlett. What inspired N.
Bartlett to prepare this compound ?
(c) Fluorine is a stronger oxidizing agent than chlorine. Why ?
(d) Write one use of chlorine gas.
(e) Complete the following equation : CaF2 + H2SO4 →
33. (a) Elements of Gr. 16 generally show lower value of first ionization enthalpy
compared to the corresponding periods of Gr. 15. Why ?
(b) What happens when
(i) concentrated H2SO4 is added to CaF2 ?
(ii) sulphur dioxide reacts with chlorine in the presence of charcoal ?
(iv)
ammonium chloride is treated with Ca(OH)2 ?
Chapter 8
(The d & f – Block elements)
5 marks
1 Mark Questions
1. What is meant by Lanthanoid contraction?
2. Name an important alloy which contains some of lanthanoid metals.
3. Why do d block elements generally exhibit large no. of oxidation states than those
exhibited by the f block elements?
4. What is Misch metal?Give its one use.
5. Based on the data arrange Fe2+,Mn2+ and Cr2+ in the increasing order of stability of +2
oxidation state
E0Cr3+/Cr2+ = -0.4V, E0Mn3+/Mn2+ = 1.5V, E0Fe3+/Fe2+ = 0.80
6. Why are transition elements so named?
7. Why does copper not replace hydrogen from acids?
8. Write the outer electronic configuration of lanthanoids.
9. Write the general electronic configuration of actinoids.
10. Why do Zr and Hf exhibit almost similar properties?
2, 3 Marks Questions
1. Complete the equations(i) oxidation of Fe2+ by Cr2O72-in acidic medium
(ii) oxidation of S2O32- by MnO4- in neutral aq. medium
2. Explain (a) Transition metals act as catalyst
(b) Cr group elements have highest m.p. in their respective series.
(c ) Transition metals form coloured complexes
3. A mixed oxide of Fe & Cr,Cr2O3 is fused with Na2CO3 in the presence of air to form a
yellow compound (A), On acidification the compound (A) forms an orange coloured
compound (B) which is strong O.A. Identify ( i ) the compounds (A) & (B)(ii)Write
balanced equation for each step.
4. Reason: (i) The T.E.generally form coloured compounds
(ii) With 3d4 configuration,Cr2+ act as a R.A.but Mn3+ act as an O.A. (at. Mass Cr=24,
Mn=25)
(iii )The actinoids exhibit a larger no. of oxidation state than the corresponding
lanthanoids.
5. Compare the relative stability of +2 oxidation state in aq. Solution for the metals having
their atoms the outer configuration 3d34S2,3d54S2& 3d64S2
6. (a) Complete (i) Cr2O72- + H+ + Fe2+ 
(ii)MnO4- + I- + H+ 
(b) How many unpaired electrons are present in Mn2+ ion?How does it influence mag.
behaviour of Mn2+ ions?
7. (a) Describe the commercial preparation of KMnO4 from pyrolusite ore.
( b ) Write ionic equation to represent the reaction of acidified KMnO4 solution with
oxalic acid.
8. (a) On what ground can you say thatSc(21) is a T.E. but Zn(30) is not?
( b)Use Hund’s rule to derive the e.c. of Ce3+ ion & calculate its magnetic moment by
using ‘spin only’formula (Ce=58)
( c )What is lanthanoid contraction & what are its consequences?
9. Complete the following reactions:
(i)
MnO4- + C2O42- + H+ 
(ii)Cr2O72- + H+ + Fe2+ 
10. How would you account for the following:
(i)Many of the T,E. and their compounds can act as good catalyst.
(ii)The metallic radii of the5 d series of T.E. are virtually the same as those of the
corresponding members of the 4 d series.
(iii)There is greater range of oxidation state among the actinoids than the lanthanoids.
11. Explain: (i)There is general increase in the density of elements from Ti to Cu
(ii)There occurs much more frequent M-M bonding in compounds of T.E. (3rd series)
(iii)The members in the actinoid series exhibit a large no. of oxidation states than the
corresponding members in the lanthanoid series.
12. Explain: (i) In general the atomic radii of T.E. decrease with at.no. in a given series.
(ii) E0 M 2+/ M for Cu is 0.34V It is the only metal in 3 d series
Showing this type of behaviour.
(iii) E0 value for Mn3+/Mn2+ couple is much more +ve than for Cr3+/Cr2+ or
Fe3+/Fe2+ couple
13. Reason :(i) The enthalpy of atomization of T,E. are quite high’
(ii) There is a greater horizontal similarity in the property ofT.E. than that of the
main group Elements.
14. Explain :
(i)
With the same d orbitals (d4) Cr2+ Is a R.A. but Mn3+ ion is an O.A.
(ii)
Cu+ ion is unstable in aq. solution
(iii)
Among 3d series of T.E. the largest no. of oxidation states are exhibited
by Mn
15. (i) Cu+ ion is unstable in aq. solution
(ii)Mn2+ ion shows maximum paramagnetic character amongst the bivalent ions of 3d
series
(iii)Sc salts are white.
16. Describe the following for first series of T.E. and their trends
(i)
atomic radii (ii) oxidation states ( iii) I.E.
17. Explain the following:
(i)
La 3+ (57) and Lu 3+ (71) do not show any colour in solution
(ii)
Among the divalent cations in the first series of T.E., Mn exhibits the maximum
paramagnetism.
(iii) Cu + is not known in aqueous solution.
18. Explain :
(i)Generally there is increase in density of elements from Ti-22 to Cu-29 in the first series
of T.E.
(ii)T.E. and their compounds are generally found to be good catalysts in chemical
reaction.
19. How would you account for the following
(i)
The at. Radii of elements of the 5 d series of T.E. arevirtually the same as those
of the corresponding members of 4 d series.
(ii)
E0 value for Mn3+/Mn2+ couple is much more +ve than for
Cr3+/Cr2+ or Fe3+/Fe2+ couple
(iii) The highest oxidation state of ametal is exhibited in its oxide or fluoride.
20. Explain:
(i)
The enthalpy of atomization of transition metals are quite high
(ii)
There is close similarity in physical and chemical property of 4d and 5 d series
of the T.E. much more than expected on the basis of usual family relationship.
(iii) The members in the actinoid series exhibit large no. of oxidation state than the
corresponding member in the lanthanoid series.
21. Explain:
(i)
The T.E. have great tendencyfor complex formation
(ii)
There is a gradual decrease in the atomic size of T.E. in a series with increasing
at.no.
(iii) La and Lu do not show colouration in the solution.(at.no La = 57,Lu = 71)
22. The sum of IE1 and IE2 ,IE3 and IE4 of Ni and Pt are
IE1+IE2 (MJ/mol)
IE3+IE4 (MJ/mol)
Ni
2.49
8.80
Pt
2.66
6.70
Based on the above information answer the following:
(a) Which is the most oxidation state for Ni and Pt?Why?
(b) Out of the two, name the metal which can easily form compounds in +4
oxidation state and why?
23. Write chemical equation for the following reactions:
(i)Oxidation of NO2- ion by MnO4- in acidic medium
(ii)Acidification ofK2Cr2O7 solution
(iii)Disproportionation of Mn(VI) in acidic solution
24. How would you account for the following:
(i) Cr2+ is reducing in nature while with the same d orbital configuration (d4) Mn3+ is an
O.A.
(ii) In a transition series of metals,the metal which exhibits the greatest no. of oxidation
state occurs in the middle of the series.
25. Give reasons:
(i)
Unlike Cr3+,Mn2+,Fe3+ and the subsequent other M2+ ions of the 3d series of
elements,the rd and the 5d seriesmetals generally do not form stable cationic c
species.
(ii)
Metal-Metal bonding is more frequent for the 4d and the 5d series of treansition
metals than that of the 3d series.
26. Explain giving reasons:
(i)
Transition metals and their compounds generally exhibit a paramagnetic behavior
(ii)
The chemistry of actinoids is not smooth as that of lanthanoids.
27. How would you account for the following:
(i)
Metal-metal bonding is more extensive in the 4d and 5d series of transition
elements than the 3d series.
(ii)
Mn(III) undergoes disproportionation reaction easily
(iii) Co(II) is easily oxidised in the presence of strong ligands.
28. complete the following chemical equations:
(i)
Fe3+ + I - 
(ii)
CrO42- + H+ 
(iii) Cr2O72- + I- + H+ 
(iv)
MnO4 - + SO3 2- +H+ 
(v)
MnO4 - + NO2 - +H+ 
29. (a) How does the acidified potassium permanganate solution react with (i) iron (II) ions
and Oxalic acid? Write the ionic equations for the reactions.
(b) Name the oxometal anion of the transition metals in which the metal exhibits the
oxidation state equal to group number.
30. Explain the following observations giving an appropriate reason for each.
(i)
The enthalpies of atomization of transition elements are quite high.
(ii)
There occur much more frequent metal-metal bonding in compounds of heavy
transition metals.
(iii) Mn2+ is much more resistant than Fe2+ towards oxidation.
5 Marks Questions
1. (a) A blackish brown coloured solid A when fused with alkali metal hydroxide in
presence of air produces a dark green coloured compound B which on electrolytic
oxidation in alkaline medium gives a dark purple compound C.Identify A,B,C& write
the reactions involved.
(b) What happens when an acidic solution of green compound B is allowed to stand for
sometime? Give the equation involved What is this type of reaction called?
2. Reasons: (a) Transition Elements have high enthalpy of atomization
(b) Among the lanthanoids,Ce (III) is easily oxidized to Ce (IV)
(c ) Fe 3+ /Fe 2+ redox couple has less +ve electrode potential than
Mn 3+ / Mn 2+ couple
(d) Cu (I) has d10 configuration while Cu (II) has d 9 configuration ,still Cu (II)
is more stable in aq. solution than Cu (I).
(e)The second & third transition series elements have almost similar atomic radii.
3. (a) Out of Ag2SO4,CuF2,MgF2& CuCl. Which compound will be coloured why?
(b) Explain: (i) CrO4 2- is strong O.A.while MnO42- not.
(ii) Zr & Hf have identical sizes
(iii)The lowest oxidation state of Mn is basic while the highest is acidic
(iv) Mn (II) shows maximum paramagnetic character amongst the divalent
ions of the first transition series.
4. (a) In the titration of FeSO4 withKMnO4 in the acidic medium, why is dil. H2SO4used
instead of HCl?
(b) Reasons: (i) Among transition metals the highest oxidation state is exhibited in
oxoanions of a metal
(ii) T.E. form a no. of interstitial compounds.
(iii)Zn2+ salts are white while Cu2+ salts are blue
(iv)Ce4+ is used as an O.A. in volumetric analysis
5. Reasons: (i) T.E. & many of their compounds act as a good catalyst.
(ii) Actinoid contraction is greater than lanthanoid contraction
(iii)The E0 value for Mn 3+ / Mn 2+ couple is much more +ve than that for Cr 3+ / Cr 2+.
(iv)Sc(21) does not exhibit variable oxidation state & yet it is regarded as a T.E.
(v) With d4 configuration , Cr2+ act as a R.A. but Mn3+ acts as an O.A.
6. (a) What may be the possible oxidation state of T.E. with the following d electronic
configuration in the ground state of their atoms 3d34S2,3d54S2& 3d64S2.Indicate
relative stability of oxidation state in each case.
(b) Write the steps involved in the preparation of:
(i)Na2CrO4 from chromite ore
(ii) K2MnO4 from pyrolusite ore
7. Reasons: (i) The actinoids exhibit a larger no. of oxidation state as compared to
Lanthanoids in general.
(ii) Though a T.E. (Sc=21) does not exhibit variable oxidation state.
(b) (i) Describe how K2Cr2O7 is prepared from chromate
(ii)The colour of K2 Cr2O7 solution changes with change in pH of solution
8. (a) Complete the equations: (i) Cr2O72- + H+ +H2S 
(ii)MnO4- + S2O32- + H2O
(b) Explain: (i)The gradual decrease in size in actinoid contraction from element
to element is greater among the actinoids than that among the lanthanoids
(ii) The greatest no. of oxidation states are exhibited by members in the middle of a
transition series.
(iii)With the same d orbitals (d4) Cr2+ Is a R.A. but Mn3+ ion is an O.A.
9. (a) What is meant by lanthanoid contraction?what is it due to and what consequences
does it have on the chemistry of elements following lanthanoid in the P.T.
(b) Explain (i) Cu+ ion is unstable in aq.solution
(ii)although Co2+ ion appears to be stable ,it is oxidized to Co3+ ion in
presence of strong ligand.
(iii)E0Mn 2+/Mn value for Mn is much more than expected from the trend
for other elements in the series.
10. (a)Complete the equations:
(i) MnO4 - + S2O3 + H2O 
(ii) Cu2+ + I - 
( b) Account for the following:
(i)The oxidizing power of oxoanins are in the order VO2 + < Cr2O7 2- < MnO4(ii)The third ionization enthalpy of Mn (25) is exceptionally high.
(iii)Cr 2+ is a stronger R.A. than Fe 2+
11. (a) give reasons for the following:
(i)
Mn3+ is a good oxidizing agent.
(ii)
E0 M2+/M values are not regular for first row transition metals (3d series)
(iii) Although F is more electronegative than O , the highest Mn fluoride is MnF4,
whereasthe heist oxide is Mn2O7.
(b) Complete the following equations:
(i)
2CrO4 2- + 2 H+ 
(ii)
KMnO4 on heating 
12. (a) Calculate the number of unpaired electrons in the following gaseous state
ions: Mn2+,Cr3+,V3+ and Fe2+. Which one of these is the most stable in
aqueous solution? (at.no. V=23,Cr=24,Mn=25,Fe=26)
(b) Explain the following observations:
(i) Oxoanions of a metal show higher oxidation state.
(ii) Explain why Ce4+ is a strong O.A.
(iii) The highest oxidation state of a transition metal is exhibited in its oxide or fluoride.
13. Account for the followinh:
(a) Eu(II) is more stable than Ce(II)
(b) T.E. have high enthalpy of atomization
(c) Actinoids are generally coloured.
(d) Cr is typical hard metalwhile He is liquid
(e) MnO is basic while Mn2O3 is acidic in nature
(f) Ag is transition metal but Zn is not
14. (a) Write the electronic configuration of Ce3+ion,and calculate the magnetic moment on
15.
the basis of spin – only formula.(Ce = 58)
(b) account for the following:
(i) the enthalpy of atomization of the transition metals are high.
(ii) the lowest oxide of a transition metal is basic, the highest is amphoteric /acidic.
(iii) Co(II) is stable in aqueous solution but in the presence of complexing agents,it is
easily oxidized
16. Explain the following observations:
(i)
Lanthanoids form primarily +3 ions , while the actinoids usually have higher
oxidation states in their compounds,+4 or even +6 being typical.
(ii)
There is a general increase in density from Ti (Z=22)to copper(Z=29)
(iii) With the same d- orbital configuration (d4) , Cr2+ is a reducing agent while
Mn3+ is an oxidizing agent.
(iv)
The metallic radii of the third (5d) series of transition metals are nearly the
same as those of the corresponding members of the second series.
(v)
Among
lanthanoids,
Ln
(III)
compounds
are
predominant.
However,occasionally in solutions or in solid compounds, +2 and +4 ions are
obtained.
(vi)
The E0M2+ /M for copper is positive (0.34V). copper is the only metal in the first
series of transition elements showing this behavior.
Chapter : 9
(Co ordination compounds )
3 marks
1 Mark Questions
1.
2.
3.
4.
5.
6.
7.
8.
9.
Why dos a tetrahedral complex of type [MA2B2] not show geometrical isomerism?
Write IUPAC name of[CoCl(NO2)(NH3)4]Cl
Write IUPAC name of[Co(NH3)6] [Cr(CN)6]
Write IUPAC name of[Cu(NH3)4] [PtCl4]
Give an example of linkage isomerism.
Give an example of ionization isomerism.
What is an ambidentate ligand? Give an example.
Give an example of coordination isomerism.
What happens to the colour of coordination compound [Ti(H2O)6]Cl3 when heated
gradually?
10. what do you understand by denticity of a ligand?
11. why is CO a stronger ligand than Cl- ?
12. Discuss the role of coordination compounds in: (a) Analytical Chemistry (b) Biological
System.
13. What do you mean by crystal field splitting energy?
14. What are inner orbital complex? Give example.
15. Give an example of a bidentate ligand.
16. Using IUPAC system, write the formula of the following compound:
Potassium
trioxalatochromate (III)
17. Explain ionization isomerism with example.
18. name the following coordination compound:
K3[CrF6]
19. Why metal carbonyls are called as organometallics?
20. Why are low spin tetrahedral complexes not formed?
2, 3 Marks Questions
1. (a) [Cr(NH3)6]3+ is paramagnetic while [Ni(CN)4]2− is diamagnetic. Explain why?
(b) Write the formula for the coordination compound Tetraamminediaquacobalt (III)
chloride.
2. A metal ion Mn+ having d4 valence electronic configuration combines with
three didentate ligands to form a complex compound Assuming ∆o >P
(i)
Draw diagram showing d orbital splitting during this complex formation
(ii)
Write the electronic configuration of valence electron of metal Mn+ in in terms of
t2g & eg.
(iii) What type of hybridization will Mn+ ion have?
(iv)
Name the type of isomerism exhibited by this complex.
3. (a) Give IUPAC name of [CrCl2(H2O)4]Cl
(b) Give the no. of unpaired electrons in [FeF6]4- & [Fe(CN)6]4(c) Name the isomerism.
[Co(NH3)5Br]SO4 &
[Co(NH3)5 SO4]Br
Give the chemical test to distinguish between these two compounds.
4. Give the electronic configuration of the
(a) d orbitals of Ti in[Ti(H2O)6]3+ ion in an octahedral crystal field.
(b) Why is this complex coloured? Explain on the basis of distribution of electron in the
d orbitals?
(c) How does he colour change on heating [Ti(H2O)6]3+ ion?
5. (a) What is a ligand? Give an example of bidentate ligand.
(b) Explain as to how the two complexes of Ni, [Ni(CN)4]2- & Ni(CO)4 have
different structures but do not differ in their magnetic behaviour. [Ni = 28]
6. (a)What is the basis of formation of the electrochemical series?
(b) Draw the structures of the geometrical isomers of following [Co(NH3)3Cl3]
& [CoCl2(en)2]+
7. Describe the limitations of V.B. theory.
8. Using V.B. approach , deduce the shape & magnetic character of
[Co(NH3)6]3+ ion (Co =27)
9. (a) Draw the structure & write the hybridization of Co in cis-[Co(NH3)4Cl2]+
(b) Write IUPAC name of[Co(NH3)4Cl(ONO)]Cl
10. Giving example for each, explain the following
(i)
Crystal field splitting
(ii)
Linkage isomerism
(iii) Ambidentate ligand
11. Compare the following complexes with respect to structural shapes of units,magnetic
behaviour& hybrid orbitals involved in units [Co(NH3)6]3+ , [Cr(NH3)6]3+,Ni(CO)4
(Co=27,Cr=24,NI=28)
12. Explain (i) Low spin octahedral complexes of Ni are not known.
(ii) The∏ complexes are known for transition elements only
(iii)CO is stronger ligand than NH3 for many metals.
13. Compare the following complexes with respect to structural shapes of
units,magnetic behaviour & hybrid orbitals involved in units
(i) [Ni(CN)4]2- (ii) [NiCl4]2- (iii) [CoF6]314. For the complex [Fe(en)2Cl2]Cl Identify
a) Oxidation no. of Fe.
b) Hybrid orbitals & shape of complex
c) Magnetic behaviour of complex
d) No. of geometrical isomers
e) Whether there is an optical isomer also
f) Name of the complex
15. Compare the following complexes with respect to structural
shapes,magnetic behavior & hybridization (i) [CoF4]2- (ii) [Cr(H2O)2(C2O4)](iii) [Fe(CN)6]416. Three geometrical isomers are possible for [Co(en)(H2O)2(NH3)2]3+. Draw
molecular structures of these three isomers & indicate which one of them
is chiral
17. Compare with respect to molecular shape and magnetic behavior
(i)
[Cr(NH3)6]3+ (ii) [Fe(CN)6]4- (iii) [NiCl4]218. Explain giving example
(i) Linkage isomerism (ii) Outer orbital complex (iii) A bidentate ligand
19. (a) Square planar complexes of (MX2L2Type) with C.N. of 4 exhibit geometrical
isomerism whereas tetrahedral complexes with similar composition do not why?
(b) Describe the type of structural shapes ,magnetic behaviour & hybridization
of [Co(NH3)4Cl2]Cl (at.no of Co =27)
20. (i) Ni does not form low spin octahedral complexes.
(ii) The∏ complexes are known for the T.E. only.
(iii) Co 2+ is easily oxidized to Co 3+ in the presence of strong ligand.
21. Write the name , the state of hybridization , shape and the magnetic behaviour of the
following :
(i) [CoCl4] 2- , [Ni(CN)4] 2- ,[Cr(H2O)2 (C2O4)2 ] –
(at. No. Co = 27 , Ni = 28 , Cr = 24)
22. Name the following coordination compounds according to IUPAC system of
nomenclature:
(i)
[Co(NH3)4(H2O)Cl]Cl2
(ii)
[CrCl2(en)2]Cl
23. Describe the shape and magnetic behavior of following complexes:
(i)
[Co(NH3)6]3+
(ii)
[Ni(CN)4]224. Describe the state of hybridization,shape and magnetic behaviour of
(i)
[Cr(H2O)2(C2O4)2](ii)
[Co(NH3)2(en)2]3+
25. (a) Give e.c. of d orbitals of Ti in [Ti(H2O)6]3+ ion and explain why this complex is
coloured? (Ti = 22)
(b) Write IUPAC name of [Cr(NH3)3(H2O)3]Cl3
26. (a) State the hybridization and magnetic behavior of [Cr(CO)6]
(b) What are the factors affecting crystal field splitting energy?
(c) Which of the two is more stable and why? K4[Fe(CN)6] or K3[Fe(CN)6]
Q16) Using Valence bond theory, predict the geometry and magnetic character of
[NiCl4]2-. (Ni = 28)
27. Explain the following terms giving suitable example in each case.
(i)
Ambident ligand
(ii)
Denticity of ligand
(iii) Crystal splitting in an octahedral field
28. Write the structures and name of all the stereoisomers of the following compounds.
(i)
[Co(en)3]Cl3 (ii)[Pt(NH3)2Cl2] (iii)[Fe(NH3)4Cl2]Cl
29. Write the state of hybridization,the shape and magnetic behavior of
(i)
[Cr(NH3)4Cl2]Cl
(ii)
[Co(en)3]Cl3
(iii) K2[Ni(CN)4]
30. write the name,stereochemistry and magnetic behavior of the following:
(Mn =25,Co=27,Ni=28)
(i)
K4[Mn(CN)6]
(ii)
[Co(NH3)5Cl]Cl2
(iii) K2[Ni(CN)4]
31. for the complex [Fe(en)2Cl2]Cl , identify the following:
(i)
Oxidation number of iron
(ii)
Hybrid orbitals and shape of the complex
(iii) Magnetic behavior of the complex
(iv)
Number of its geometrical isomers
(v)
Whether there may be optical isomer also
(vi)
Name the complex.
32. name the following coordination compounds and draw their structures:
(i)
[CoCl2(en)2]Cl
(ii)
[Pt(NH3)2Cl(NO2)]
(Co=27,Pt=78)
33. draw the structures of isomers ,if any, and write the names of the following
complexes:
(i)
[Cr(NH3)4Cl2]+
(ii)
[Co(en)3]3+
(Cr=24,Co=27)
34. give the name ,the stereochemistry and the magnetic behavior of the
following complexes:
(i)
[Co(NH3)5Cl]Cl2
(ii)
K2[Ni(CN)4]
35. (a) square planar complexes(of MX2L2 type) with coordination number of 4
exhibit geometrical isomerism whereas tetrahedral complexes with similar
composition, do not. why?
(d) describe the type of hybridization,shape and magnetic property of
[Co(NH3)4Cl2]Cl
(Co=27)
36. write the IUPAC name and deduce the geometry and magnetic behavior of the complex
K4[Mn(CN)6]
(Mn=25)
37. name the following coordination entities and draw the structures of their
stereo isomers:
(i)
[Co(en)2Cl2]+
(ii)
[Cr(C2O4)3]3(iii) [Co(NH3)3Cl3]
( atomic no. Cr = 24 , Co = 27)
38. name the following coordination entities and draw the structures :
(i)
[Fe(CN)6]4 –
(ii)
[Cr(NH3)4Cl2]+
(iii) [Ni(CN)4]2(atomic no. Fe = 26, Cr = 24, Ni = 28)
39. Give the formula of each of the following coordination entities.
(i)
Co3+ ion is bound to one Cl- , one NH3 molecule and two bidentate ethylene
diamine molecules
(ii)
Ni2+ ion is bound to two water molecules and two oxalate ions.
Write the name and magnetic behavior of each of the above coordination
entities.(at.no.Co=27,Ni=28)
40. State reasons for each of the following situations:
(i)
Co2+ is easily oxidized to Co3+ in presenceof strong ligand
(ii)
CO is a stronger complexing reagent than NH3
(iii) The molecular shape of Ni(CO)4 is not same as that of [Ni(CN)4]241. write the name,the structure and the magnetic behavior of each one of the
following complexes:
(i)
[Pt(NH3)2Cl(NO2)]
(ii)
[Co(NH3)4Cl2]Cl
(iii) [Ni(CO)4]
(at.no. Co=27,Ni=28,Pt=78)
42. Explain the following:
(i)
The ∏ complexes are known for transition elements only.
(ii)
Nickel(II) does not form low spin octahedral complexes.
(iii) [Fe(CN)6]4- and [Fe(H2O)6]2+ are of different colours in dilute solutions.
43. Name the following complexes and draw the structures of one possible
isomer of each:
(i)
[Cr(C2O4)3]3(ii)
[Pt(NH3)2Cl2]
(iii) [Co(en)2Cl2]+
44. For the complex [NiCl4]2- , write
(i)
The IUPAC name.
(ii)
The hybridization type.
(iii) The shape of the complex
(Atomic no. of Ni =28)
45. what is meant by crystal field splitting energy? On the basis of crystal field theory ,write
the electronic configuration of d4 in terms of t2g and eg in an octahedral field when
(i)
∆o > P
(ii)
∆o < P
Chapter : 10
(Haloalkanes & Haloarenes)
4 marks
IUPAC
1. IUPAC name of CH3CH=C(CH3)CH(Br)CH3
2. IUPAC name of CH3CH=C(CH3)CH2Br
3. IUPAC name of CH3C(CH3)=C(Br)CH2OH
4. IUPAC name of CH3CH=CHCH2Br
5. IUPAC name of
6. Draw the structure of following compound.
4-Bromo-3-methylpent-2-ene
7. Draw the structure of following compound.
1-Bromo-4-sec-butyl-2-methyl benzene
8. IUPAC name of CH2=CHCH2Br
9. CH3CH=C(CH3)CH2Br
10. write the IUPAC name of (CH3)3CCH2Br
11. write the structure of the compound 4-tert.Butyl-3-iodoheptane.
12. write IUPAC name of neopentyl chloride
13. write the structure of 1-Chloro-4-ethylcyclohexane.
14. write the structure of 1,4-Dibromobut-2-ene
15. write IUPAC name of following. CH2 = C(CH3)-CH2Br
16. write the IUPAC name of the following compound:
Benzene ring 1and 4 position Cl and 3 position CH3 gr.
17. write the IUPAC name of the following compound: CH3CH(Br)CH2CH(Cl)CH3
18. Write IUPAC name of the following:
CH3 C (CH3)2 CH (Cl) CH3
19. Write the IUPAC name of CH3CH(Br)CH2CONHCH3.
20. Write the IUPAC name of the following compound (CH3)2 CHCH2 Br.
MECHANISM
1. An optically active compound having M.F.C7H5Br reacts with aq.KOH to give
racemic mixture of products. Write the mechanism.
2. Discuss the mechanism of SN1 reaction of haloalkanes
3. Suggest a possible mechanism for the following
n-BuBr + KCN (ethanol/H2O  n-BuCN
4. How would you differentiate between SN1 and SN2 mechanism of
substitution reaction ? Give one example of each.
5. Propose mechanism of the reaction taking place when
(i)
(-)-2-Bromooctane reacts with NaOH to form(+)-octan-2-ol
(ii)
2- Bromopentane is heated with alc. KOH to form alkenes
6. suggest a possible mechanism for the following reaction:
n-BuBr + KCN (ETOH , H2O )  n- BuCN
7. Write difference between SN1 and SN2 REACTIONS. Which alkyl halide from the
following pairs would you expect to react more rapidly by an SN2 mechanism? Explain
your answer.
(i)
CH3CH2CH2CH2Br & CH3CH2CH(Br)CH3
(ii)
REASONS
1. Explain as to why haloarenes are much less reactive than haloalkanes
Towards Nucleophilic substitution reaction.
2. Which compound in the following pairs will react faster in SN2 reaction with
–OH & why?(i)CH3Br or CH3I (ii) (CH3)3CCl or CH3Cl
3. Which compound in the following pairs will undergo SN2 reaction
faster
why?C6H11CH2Cl or C6H11Cl
4. (i)Why is it that haloalkanes are more reactive than haloarenes towards nucleophile.
(ii) Which one of the following reacts faster in SN1 reaction & why?
CH3CH2C(Cl)CH2CH3 or CH3CH2CH2CH2Cl,
5. Reason: (a) The order of reactivity of haloalkane is RI > RBr>RCl
(b)Neopentylchloride does not follow SN2 mechanism
6. (a) Which of the following compounds would react faster by SN2 path
(1-Bromobutane or 2-Bromobutane) &why?
(b) Allyl chloride is more reactive than n- propyl chloride towards nucleophilic
substance reaction explain why?
(c) Haloalkanes react with KCN to give alkyl cyanide as main product while with AgCN
they form isocyanide as main product. Give reason.
7. (a) Which will have a higher b.p. 1-chloropentane or 2-chloro-2-methyl butane
(b) Give reason:p- nitrochlorobenzene undergoes nucleophilic substitution faster than
chlorobenzene.Explain giving the resonating structures as well.
8. Answer
(i)Identify chiral in CH3CHOHCH2CH3 and CH3CHOHCH3
(ii)Among the following compounds which one is more easily hydrolysed and
why?CH3CHClCH2CH3 or CH3CH2CH2CH2Cl
(iii)Which of these will react faster in SN2 displacement and why?
1-Bromopentane or 2-Bromopentane
9. Which is more easily hydrolysed by KOH and why?
CH3CHClCH2CH3 or CH3CH2CH2CH2Cl
10. Account for the following:
(i)Chloromethane reacts with AgCN to form methyl isocyanide as chief product
(ii) Use of DDT was banned in United States in 1973
(iii)Benzyl halides show high reactivity towards SN1 reaction
11. Iodoform has antiseptic property.Give reason to support this.
12. In each of the following pairs of organic compounds. Identify the compound
which will undergo SN1 reaction faster? (a) (CH3)3Cl & CH3CH2CH(Cl)CH3
(b) C6H5Cl & C6H5CH2Cl
13. The treatment of an alkyl chloride with aq. KOH leads to the formation of an
Alcohol whereas in the presence ofalc.KOH , alkene is the major product.
14. A solution of KOH hydrolyses CH3CHClCH2CH3 and CH3CH2CH2CH2Cl
Which will be hydrolysed easily?
15. Answer the following:
i.
Haloalkanes easily dissolve in organic solvent, why?
ii.
What is known as a racemic mixture? give an example.
iii.
Of the two bromoderivatives,C6H5CH(CH3)Br and C6H5CH(C6H5)Br which on is
more reactive in SN1 substitution reaction and why?
16. suggest a possible reason for the following observations:
i.
The orderof reactivity of haloalkanes is RI > RCl > RBr.
ii.
Neopentyl chloride does not follow SN2 mechanism.
iii.
Ethers have low boiling points.
17. Explain why
i.
The dipole moment of chlorobenzene is lower than that of cyclohexyl chloride.
ii.
Alkyl halides though polar are immiscible with water.
iii.
In the pair, (CH3)3CCl and CH3Cl,CH3Cl will react faster in SN2 reaction with –
OH.
18. Answer the following questions:
(i)
Which one of the following compounds is more easily hydrolysed by KOH and
why?
CH3CHClCH2CH3 or CH3CH2CH2Cl
(ii)
Which one undergoes SN2 sustitution reaction faster and why?
CH3CH2CH2CH2CH2I or CH3CH2CH2CH2CH2Cl
19. Although chlorine is an electron withdrawing group, yet it is ortho,para-directing in
electrophilic aromatic substitution reactions.Explain why it is so?
20. Give reason for the following:
i.
Ethyl iodide undergoes SN2 reaction faster than ethyl bromide.
ii.
(+_) 2- Butanol is optically inactive.
iii.
C-X bond length in halobenzene is smaller than C-X bond length in CH3-X
21. Explain as to why
i.
Alkyl halides,though polar,are immiscible with water.
ii.
Grignard reagent should be prepared under anhydrous conditions.
22. Although chlorine is an electron withdrawing group, yet it is ortho-, Para- directing in
electrophilic aromatic substitution reactions. Why?
23. a) Preparation of haloalkane with Alkane and halogen using U.V light is least Preferred
method why?.
b) Toluene undergoes Electrophillic substitution reaction more easily than Benzene.
Explain.
24. (a) Allyl chloride is more reactive than n-propyl chloride towards nucleophilic
substitution reaction. Explain why?
(b) Halo alkanes react with KCN to give alkyl cyanide as main product while with
AgCN they form iso cyanide as main product. Give reason.
25. Account for the following:
(i)
ρ Dichlorobenzene has higher m.p. than ortho and m-isomer.
(ii)
neo-pentyl bromide undergo nucleophilic substitution reactions very slowly.
(iii) Alkyl halides, though polar, are immiscible with water?
CONVERSION/WORD PROBLEM
1. How will you bring about following conversion
Methyl bromide to methyl iodide.
2. How would you carry out the following conversions?
(i) Ethyl magnesium chloride to propan-1-ol
(ii) Benzyl chloride to benzyl alcohol
3. How will you bring about following conversions? (i) Chlorobenzene to phenol. (ii) isopropyl bromide to n-propyl bromide (iii) Aniline to iodo benzene.
COMPLETE EQUATIONS
1. Write the main product
(i) (CH3)2CHCl + Na (dry ether )
(ii) CH3Br + AgF + Heat 
(i)
CH3CH2Br + NaI (dry acetone)
(ii)
C6H5N2Cl + Cu/HCl 
(iii)Complete CH3CH2CH=CH2 + HBr (peroxide) 
2. Complete the reaction: (i) C6H5N2Cl + KI 
(ii) CH2=CH2 + Br2 (CCl4)
(i) C6H11OH + SOCl2 
3. Write the major product
(i)
CH3CH=C(CH3)2 + HBr 
(ii) C6H5ONa + C2H5Cl 
4. Complete the reaction
CH3CH=CH2 + HBr (peroxide) X +NaI(acetone)Y
5. complete the following reaction equation:
(i)
1-Methylcyclohexene + HI 
(ii)
C6H5 CH = CH2 + HBr 
(iii) CH3CH2CH =CH2 + HBr 
6. Write the main product formed in the following chemical reactions
(a)
CH3
CH3
DRY ETHER
H3C
(b) H3C
C
H
Cl
Br
+ 2Na + Cl
+
AgF
C
H
HEAT
CH3
2
Other Important Questions
1. (i) State one use of each DDT and Iodoform
(ii) Which couple reacts faster in SN2 displacement and why?
(a)1-Bromopentane
Bromopentane or 2-Bromopentane
2
(b) 1-Bromo-2-methyl
methyl butane or 2-Bromo-2-methyl
2
butane
2. Explain:
(i)G.R. should be prepared under anhydrous condition.
(ii)C6H5CHClCH3 is hydrolysed more easily with KOH than C6H5CH2Cl.
3. Arrange the following in the decrease order of reactivity towards SN2 displacement
reaction and give reason in support of your answer.
(i) C2H5Br ,C2H5I ,C2H5Cl.
(ii)(CH3)3CBr ,CH3CH2CHBrCH3 , CH3CH2CH2CH2Br
4. Rearrange the compounds of each of following set in order of reactivity towards SN2
displacement
(i)2-Bromo-2-methylbutane
methylbutane , 11-Bromopentane ,2-Bromopentane
Bromo-2-methyl
(ii) 1-Bromo-3-methyl
methyl butane , 2-Bromo-2-methyl
2
butane , 3-Bromo
Butane
methyl butane
(iii)1-Bromo
Bromo butane ,1
,1-Bromo-2,2-dimethyl propane ,1-Bromo-2-methyl
5. What happens when bromine attac
attacks CH2 = CH-CH2-C ≡ CH
6. What is meant by chirality of a compound?give an example.
7. What are ambident nucleophiles? Explain giving an example.
8. Give the chemical tests to distinguish between compounds in the following pairs:
chlorobenzene & ethyl chloride
9. Write the isomers of the compound having formula C4H9Br.
10. Answer the following questions:
(i) What is meant by chirality of a compound? Give an example.
(ii) Which one of the following compounds is more easily hydrolyzed by KOHand why?
CH3CHClCH2CH3 or CH3CH2Cl
11.
In the following pairs of halogen compounds, which compound undergoes faster SN1
reaction?
(i)
(ii)
12. what happen when bromine attacks CH3=CH-CH2-CCH?
Wurtz13. Write the equations for the following reactions: (i) Sandmeyer’s reaction (ii) Wurtz
Fitting reaction.
14. Distinguish between the following pair: (i) Bromo benzene & benzyl bromide (ii)
nPropyl alcohol & iso--propyl alcohol.
15. Predict the alkenes that would be formed by dehydrogenation of the following halides
with sodium ethoxide in ethanol and identify the major alkene.
(i)
1-Briomo -1methylcyclohexane (ii) 2-Chloro-2-methylbutane
(ii)
2, 2, 3-Trimethlyl-3-bromopentance.
16. Primary alkyl halide C4H9Br ( ) a reacted with alcoholic KOH to give compound ( ) b .
Compound( ) b is reacted with HBr to give( ) c which is an isomer of( ) a . When ( ) a
was reacted with Na metal, it gave a compound( ) d C8H18 which is different from the
compound formed when n-butyl bromide is reacted with sodium. Give the structural
formula of ( ) a and write the equation for all the reactions.
Chapter : 11
(Alcohols, Phenols , Ethers)
4 marks
IUPAC
1)
2)
3)
4)
5)
6)
7)
8)
9)
10)
11)
12)
13)
14)
15)
16)
(CH3)2CH-CH2-CH(OH)-CH(CH3)-CH2OH
CH3-O-CH2-CH(CH3)-CH2-CH3
4-Chloropentan-2-one
CH2=CH-CH(OH)-CH2-CH2-CH3
(CH3)2C(OH)-CH2-CO-CH3
2-Methyl-2-ethoxy pentane
Write structure of 1- phenylpropan -2- ol
Write the structure of phenyl isopentyl ether
Draw the structure of 2,6-dimethyl phenol
write IUPAC name of (CH3)2C = C(Br) CH2OH
write IUPAC name of (CH3)2C(OH)CH2 CO CH3
Draw structural formula of 2-methylpropan-2-ol.
write structure of 2-methyl-2-thoxypentane
Draw the structure of Hex-1-en-3-ol.
Write the IUPAC name of CH3 CH=CH-CH(OH)CH2CH3.
Write the IUPAC name of CH3O CH2CH(CH3)2.
MECHANISM
1)
2)
3)
4)
5)
Formation of diethyl ether from ethyl alcohol.
Alcohols reacts both as electrophile & as nucleophiles in their reactions
Acid catalysed dehydration of an alcohol forming an alkene
Acid catalysed hydration of an alkene forming an alcohol
Preparation of ethoxyethane from ethanol.Does the reaction follow SN1 or SN2 pathway.
REASONS
1)
2)
3)
4)
5)
6)
Ethoxy ethane is soluble in water?
Phenol is more acidic than ethanol
Which is stronger acid phenol or cresol? Why?
Phenols do not give protonation reaction readily?
m- amino phenol is stronger acid than o- aminophenol
Alcohols act as weak base.
7)
8)
9)
10)
11)
12)
13)
14)
15)
16)
Propanol has higher b. p. than that of hydrocarbon Butane.
Preparation of ether by acid dehydration of 20 &30 alcohol is not a suitable method
Ethanol has higher b.p. than methoxy methane.
o- & p- nitrophenols are more acidic than phenol
Ethers have low b.p.
The b.p. of ethanol is higher than that of methoxy methane
o-nitrophenol is more acidic than o-methoxy phenol
Alcohols are more soluble in water than the hydrocarbons of comparable molecular masses.
Para-amino phenol is less acidic than phenol.
Anisole reacts with HI to give phenol and methyl iodide and not iodobenzene and
methylalcohol.
17) Phenol is acidic and hexanol is neutral towards a solution of NaOH.
CONVERSIONS
1)
2)
3)
4)
5)
6)
7)
8)
9)
10)
11)
12)
13)
14)
1)
2)
3)
4)
5)
Ethyl alcohol to acetaldehyde
Butan-2-one to Butan-2-ol
Phenol to 2,4,6-tribromophenol
phenol to benzoquinone
Propanone to 2- Methyl propan-2-ol
Propene to Propan- 2- ol
Benzyl chloride to Benzyl alcohol
Methyl Mg Bromide to 2-Methyl propan-2-ol
Ethyl Mg Bromide to propan-1-ol
Ethenol to ethane
Phenol to salicylaldehyde
Methanol to etahanol
Anisole to 4-methoxyacetophenone
Aminobenzene to phenol
Reimer Tiemann reaction
Williamson’s synthesis
Kolbe’s reaction
Friedel Crafts alkylation reaction
Friedel Craft acylation
NAMED REACTIONS
1)
2)
3)
4)
5)
6)
7)
8)
9)
DISTINGUISHING TEST
phenol & cyclohexanol
Propan-2-ol & benzyl alcohol
Phenol & benzyl alcohol
Butan-2-ol & 2-Methyl propan-2-ol
Ethanol & phenol
1- propanol & 2- propanol
Phenol & benzoic acid
Isopropyl alcohol and n-propyl alcohol
Methyl ethanoate and ethyl methanoate
OTHER IMPORTANT QUESTIONS
1) Name the reagents & write chemical equation for preparation of
(a) ethoxy benzene
(b) 2- Methyl-2-methoxy propane
2) Addition of G.R. to a carbonyl group of a comp. forming an adduct followed by hydrolysis?
3) Acid catalysed dehydration of an alcohol forming an alkene
4) Acid catalysed hydration of an alkene forming an alcohol
5) How do you account for the miscibility of ethoxy ethane with water?
6) Which is a stronger acid phenol or cresol?Explain
7) Give possible explaination for the following
(a) o-nitrophenol is more acidic than o-methoxy phenol
(b) Alcohols are easilyprotonated in comparison to phenol.
(c) The relative ease of dehydration of alcohol is 30>20>10
8) How would you obtain
(i) Picric acid (2,4,6 – trinitrophenol) from phenol
(ii) 2-Methylpropene from 2- Methylpropanol
9) How would you obtain
(i) Benzoquinone from phenol
(ii)
Propan-2-ol from propene
(iii)
2-Methylpropan-2-ol from methyl magnesium bromide
10) State the products of the following reactions:
(i) CH3CH2CH2OCH3 + HBr 
(ii)
C6H5OC2H5 + HBr 
(iii)
(CH3)3COC2H5 + HI 
11) Explain the mechanism of the following reaction:
CH3-CH2-OH (H+ and 443 K)  CH2=CH2 + H2O
12) Of the two alcohols:
a. CH2=CHCH2OH
b. CH2=CHCH2CH2OH,
Which one will react more easily with conc. HCl in the presence of ZnCl2?
13) Write the products obtained when benzyl phenyl ether is heated with HI.
14) Arrange the following alcohols in the order of increasing reactivity towards Lucas reagent: 2butanol,1-butanol, 2-methyl-2-propanol.
15) Write the equations of the reactions which takes place when
i. Thionyl chloride is treated with 2-propanol.
ii. Cumene hydroperoxide is treated with dil. H2SO4.
16) An organic compound (A) having molecular formula C6H6O gives a characteristics colour with
aqueous FeCl3 solution.(A) on treatment with CO2 and NaOH at 400 K under high pressure gives
(B) which on acidification gives a compound (C).C reacts with acetyl chloride to give (D).which is
a popular Pain killer. Deduce the structures of A,B,C and D.
Chapter : 12
(i)
(ii)
(iii)
(iv)
(v)
(vi)
(vii)
(viii)
(ix)
(x)
(xi)
(xii)
(xiii)
(xiv)
(xv)
(xvi)
(xvii)
(xviii)
(xix)
(xx)
(xxi)
(xxii)
(xxiii)
(xxiv)
Aldehydes, Ketones & Carboxylic acids
6marks
IUPAC
(CH3)2C=CHCOCH3
4-Methylpent-3-en-2-one (chemical formula)
CH3COCH2COCH3
CH3COCH2CH(Cl)CH3
CH3C≡CCH=CHCOOH
OHC6H5COC6H5OH
C6H5CON(CH3)2
1-Phenylpentan-1-one (chemical formula)
3-Oxopentanal (chemical formula)
(CH3)2CHCOCH(CH3)2
CH3CH2COC6H5
2-Methylcyclopent-3-enecarboxylic acid (chemical formula)
(CH3)2C=CHCOCH3
4-Chloropentan-2-one (chemical formula)
2,6-Dimethyl phenol (chemical formula)
3-Methylbutanal (chemical formula)
(CH3)2C(OH)CH2COCH3
CH2CH2CH2CHCHO(cyclic structure)
C6H4Cl COCH3
CH3-CH2-CH = CH- CHO
Ph-CH = CH –CHO
3-Methylbutanal
Hexane-1,6-dioic acid
p-Nitropropiophenone
REASONS
(i)
(ii)
(iii)
(iv)
(v)
(vi)
(vii)
(viii)
(ix)
(x)
Aldehydes are more reactive than ketones towards nucleophile
The b.p. of aldehydes & ketones are lower than corresponding acids.
The aldehydes & ketones undergo a no. of addition reactions
Monochloroethanoic acid has a higher pKa value than dichloroethanoic acid
Ethanoic acid is weaker acid than benzoic acid
Benzoic acid does not undergo F/C reaction.
pKa value of chloroacetic acid is lower than pKa value of acetic acid.
P-nitrobenzoic acid has higher Ka value than benzoic acid
Acetone is highly soluble in water but benzophenone is not.
Ethanal is soluble in water.
CONVERSIONS
a)
b)
c)
d)
e)
f)
g)
h)
i)
j)
k)
l)
m)
n)
o)
p)
q)
r)
s)
t)
u)
v)
w)
x)
y)
z)
aa)
bb)
cc)
dd)
ee)
ff)
Ethyl benzene to benzene
Acetaldehyde to Butan-1,3-diol
Acetone to propene
Ethanol to acetone
Benzene to acetophenone
Benzoic acid to benzaldehyde
Propanone to Propene
Bromobenzene to 1-Phenylethanol
Benzoic acid from ethylbenzene
Benzaldehyde from Toluene
Ethanol to 3- Hydroxybutanal
Bezaldehyde to Benzophenone
Cyclohexanol to cyclohexan-1-one
Ethyl benzene to benzoic acid
Bromobenzene to benzoic acid
Ethyl cyanide to ethanoic acid
Butan-1-ol to butanoic acid
Methyl benzoic acid to benzoic acid
Ethanal to but-2-enal
Benzene to bezaldehyde
Benzene to acetophenone
Ethyl cyanide to 1-phenyl propanone
Butanoic acid from butanol
Propanone to Prpan-2-ol
Ethanal to 2-hydroxy propanoic acid
Toluene to benzoic acid
Butan-1-ol to butanoic acid
4-Methylacetophenone to benzene-1,4-dicarboxylic acid
Benzoic acid to m-bromobenzoic acid
Ethanal to 3-Hydroxybutanal
Benzoic acid to m-nitrobenzyl alcohol
Benzaldehyde to Benzophenone
NAMED REACTIONS
(i)
(ii)
(iii)
(iv)
Cannizzaro’s reaction
Cross aldol condensation
Decarboxylation
Acetylation
(v)
(vi)
(vii)
(viii)
(ix)
(x)
(xi)
(xii)
(xiii)
(xiv)
(xv)
Hell-Volhard-Zelinsky reaction
Clemmenson’s Reduction
Rosenmund’s reduction
Wolf -Kishner reduction reaction
Aldol condensation
Etard reaction
Gatterman-Koch reaction
Stephen reaction
Iodoform test
Tollen’s test
Fehling test
DISTINGUISHING TESTS
(i)
(ii)
(iii)
(iv)
(v)
(vi)
(vii)
(viii)
(ix)
(x)
Acetaldehyde & benzaldehyde
Propanone & propanol
Propanal & propanone
Phenol & benzoic acid
Acetophenone & benzophenone
Ethanal & propanal
Benzoic acid & Ethyl benzoate
Formic acid and acetic acid
Benzaldehyde and acetophenone
Pentan-2-one and Pentan-3-one
WORD PROBLEM
1.
An organic compound (A) having M.F. C8H8O forms an orange red ppt (B) with 2,4-DNP reagent.
Compound (A) gives a yellow ppt (C) when heated in presence of I2 & NaOH alongwith a
colourless compound (D). (A) does not reduce Tollen’s reagent or Feh. Soln. nor does it
decolourise Br2 water. On drastic oxidation of (A) with chromic acid,a carboxylic acid (E) of M.F.
C7H6O2 is formed. Deduce the structures of org. compds. (A) to (E).
2. An organic compound A with M.F. C5H8O2 is reduced to n-pentane on treatment with Zn-Hg/HCl.
A forms a dioxime with hydroxylamine &gives a positive iodoform test & Tollen’s test Identify
the compound A & deduce its structure.
3. An organic compound (A) on treatment with acetic acid in the presence of sulphuric acid
produces an ester (B). (A) on mild oxidation gives (C) (C) with 50%KOH followed by acidification
with dilute HCl generates (A) and (D).(D)with PCl5 followed by reaction wit ammonia gives (E).(E)
on dehydration produces hydrocyanic acid. Identify the compounds A,B,C,D,E .
4. An unknown aldehyde A on reacting with alkali gives β-hydroxyaldehyde which loses water to
form an unsaturated aldehyde , 2- butenal. Another aldehyde B undergoes disproportionation
reaction in presence of conc. alkali to form products C & D. C is aryl alcohol with the formula
C7H8O.
(i)
Identify A & B
(ii)
Wrute the sequence of reactions involved.
(iii)
Name the product when B reacts with Zn/Hg & HCl.
5. A compound X (C2H4O) on oxidation gives Y (C2H4O2). X undergoes haloform reaction. On
treatment with HCN , X forms a product Z which on hydrolysis gives 2- hydroxyl propanoic acid.
(i)
Write structures of X & Y
(ii)
Name the product when X reacts with dil. NaOH
(iii)
Write the equation for the reactions involved.
6. An organic compound contains 69.77% C ,11.63% H ,& rest is O. The molar mass of the
compound is 86. It does not reduce Tollen’s reagent but forms an addition compound with
NaHSO3 & gives a positive iodoform test. On vigorous oxidation it gives ethanoic & propanoic
acid. Deduce the possible structure of organic compound.
7. An org. compd. A (C7H6Cl2) on treatment with NaOH soln. gives another compd. B (C7H6O). B on
oxidation gives an acid C (C7H6O2) which on treatment with a mixture of conc. HNO3 &
conc.H2SO4 gives a compd. D (C7H5NO4). B on treatment with conc. NaOH gives a compd E
(C7H8O) & C6H5COONa. Deduce structures of A,B,C,D,E.
8. An org. compd. A having M.F. C8H16O2 was hydrolysed with dil. H2SO4 to give a carboxylic acid
B& an alcohol C. Oxidation of C with chromic acid produces B.C on dehydration gives But-1ene.Write equations for the reactions involved.
9. An org. comp. A (C3H6O) is resistant to oxidation but forms comp. B(C3H8O) on reduction reacts
with HBr to form the comp. C. C with Mg forms G.R. D which reacts with a to form a product
which on hydrolysis gives E. Identify A to E.
10. Identify A to E.
A [O] B + Ca(OH)2 C +Distl D +LiAlH4[H]E + HBrCH3CH(Br)CH3
11. An org. comp. A on treatment with acetic acid in presence of H2SO4 produces an ester B. A on
mild oxidation gives C.C with 50% KOH followed by acidification with dil HCl generates A & D. D
with PCl5followed by reaction with NH3 gives E. E on dehydration produces HCN Identify the
comp. A,B,C,D,E.
12. Identify the comp. A,B,C,D,E.
A +Cl2 CHCl3+NaOH  B+ C6H5COCl C C6H6/AlCl3D + E
13. An organic compound (A) which has characteristic odour. On treatment with NaOH it forms two
compounds (b) and (C).Compound (B) has M.F. C7H8O which on oxidation gives back (A).The
compound (C) is a sodium salt of an acid.When (C)is treated with sodalime it yields an aromatic
hydrocarbon (D).Deduce the structure of A, B, C, D. Write the sequence of reactions involved.
14. An organic compound X undergoes acid hydrolysis to form two compounds Y and Z.Y reacts with
Na2CO3 to form A, A is heated with sodalime to form B(CH4). Y on reduction with LiAlH4 forms Z.
Identify X, Y,Z,A,B and write the reactions involved.
15. An organic compound A has M.F. C5H10O.It does not reduce Tollen’s reagent but forms an
orange ppt. with 2,4-DNP reagent. It forms a carboxylic acid B with M.F. C3H6O. When treated
with alk. KMnO4. Yellow ppt. on treatment with NaOH and I2 under vigorous conditions.On
oxidation it gives ethanoic acid and propanoic acid. Sodium salt of B gave a Hydrocarbon C in
Kolbe’s electrolytic reduction.Identiy A, B,C and write the reactions involved.
16. Predict the products formed:
(i)
A reacts with PhMgBr and is then hydrolysed
(ii)
A reacts with hydrazine and then heated with KOH and ethylene glycol.
17. An organic compound A on treatment with ethyl alcohol gives a carboxylic acid B and
compound. Hydrolysis of C under acidified condition gives B and D. Oxidation of D with KMnO4
also gives B. B on heating with Ca(OH)2 gives E having molecular formula C3H6O. E does not give
Tollen’s test and doesnot reduce Fehling’s solution but forms a 2,4-dinitrophenyl hydrazone.
Identify A,B,C,D and E.
18. An organic compound with molecular formula C9H10O forms 2,4-DNP derivative, reduces Tollen’s
reagent and undergoes Cannizaro’s reaction. On vigorous oxidation it gives 1,2benzenedicarboxylic acid. Identify the compound.
COMPLETE EQUATIONS
1)
2)
3)
4)
5)
6)
7)
8)
9)
10)
11)
12)
13)
C6H5COCl +H2(Pd-BaSO4) 
C6H6+ ----------- (anhy.AlCl3)C6H5COCH3
C6H6 + ------------ C6H5COC6H5
Ethyl benzene (KMnO4/KOH ) and heat 
Phthalic acid (SOCl2) and heat 
Benzamide (H3O+) and heat 
HOOCC6H4COOH + SOCl2
C6H5CHO + (H2NCONHNH2 )
C6H10=CH2  C6H11CHO
CH3 CO CH3 (Zn-Hg , conc. HCl)
CH3 CO Cl + H2 (Pd –BaSO4)
C6H5COOH (Br2/FeBr3) 
Identify (A) to (E)
(i)
(A) + (B) +dil. NaOH  (C) + H2O
(ii)
(C) + O3 /Zn/H2O  (A) + (D)
(iii)
(D) +H2/Ni &Heat  (E)
14) Identify A,B,C
(iii)
A + H2 + Pd /BaSO4 (CH3)2CHCHO
(iv)
(CH3)3C-CO-CH3 + NaOI  B + C
15) Identify A,B and C in the following
C2H2 + (dil.H2SO4/HgSO4)A (dil. NaOH)  B on heatingC
16) Fill the missing X,Y,Z.
(i)
C6H5CHO + CH3CH2CHO +(NaOH)  X
(ii)
CH3CH2CH2CH2OH + (Y) CH3CH2CH2COOH
(iii)
CH3(CH2)9COOC2H5 + (Z) CH3(CH2)9CHO
17) Identify A,B,C,D,E in the following sequence of reactions:
A (Cl2) CHCl3 (NaOH) B (C6H5COClC (C6H6 /AlCl3D + E
18) Identify A,B,C,D and E.
C6H5CH3 + CrO3 + (CH3CO)2O (273-283K) A (heat,H2O) B (conc.NaOH) C+
C6H5CH3(KMnO4,KOH ,HEAT) D ( H3O+) E
C6H5COONa +
OTHER IMPORTANT QUESTIONS
1) Arrange in increasing order of their acid strength
(i)
(CH3)2CHCOOH ,CH3CH2CH(Br)COOH , CH3CH(Br)CH2COOH
(ii)
Benzoic acid , 4-Nitrobenzoic acid,3,4-Dintrobenzoic acid , 4- Methoxy benzoic acid
(iii)
CH3CH2CH(Br)COOH,CH3CH(Br)CH2COOH,(CH3)2CHCOOH,CH3CH2CH2COOH
(iv)
(reactivity towards HCN)-acetaldehyde,acetone,Di-terbutylketone,methyl ter butyl ketone
2) What is Tollen’s Reagent?Write one usefulness of the reagent.
3) Write two important uses of formalin.
4) How would you obtain:
(i)
But-2-enal from ethanol
(ii)
Butanoic acid from butanol
(iii)
Benzoic acid from ethyl benzene
5) Which of each pair shown here would you expect to e stronger?
(i)
F-CH2-COOH or Cl-CH2-COOH
(ii)
C6H5OH or CH3COOH
6) Rearrange the following compounds in the increasing order of their b.p.
CH3CHO ,CH3CH2OH , CH3CH2CH3
7) Arrange the following compounds in an increasing order of their property as indicated:
(i)
Acetaldehyde,acetone,methyl tert-butyl ketone (reactivity towards HCN)
(ii)
Benzoic acid,3,4-dinitro benzoic acid ,4-methoxy benzoic acid (acid strength)
(iii)
CH3CH2CH(Br)COOH,CH3CH(Br)CH2COOH,(CH3)2CHCOOH (acid strength)
8) Arrange the following compounds in an increasing order of their reactivity in nucleophilic addition
reactions: ethanol, propanal , propanone , butanone.
9) Describe the mechanism of the addition of Grignard reagent to the carbonyl group of a compound
to form an adduct which on hydrolysis yields an alcohol.
10) Explain the mechanism of a nucleophilic attack on the carbonyl gr. Of an aldehyde or a ketone.
Chapter: 13
1)
2)
3)
4)
5)
6)
7)
(Organic compounds containing nitrogen)
IUPAC
4 marks
CH3-N(C2H5)-CO-CH3
H2NCH2CH2CH=CH2
C6H5NHCH3
n-methyl ethanamine (structure)
2-aminotoluene (structure)
prop-2-en-1-amine (structure)
N, N-diethyl butyl amine (structure)
REASONS
1) Direct nitration of aniline is not carried out. Explain why?
2) Predict giving reason the order of basicity (i) gaseous phase (ii) in aqueous solution
(CH3)3N , (CH3)2NH , CH3NH2,NH3
3) pKb for aniline is more than methylamine
4) Methyamine solution reacts with FeCl3 solution to give ppt of Fe(OH)3
5) Primary amines have higher b.p. than tertiary amine.
6) AgCl dissolves in aq. Methylamine solution
7) Presence of a base is needed in the ammonolysis of alkyl halide.
8) Aromatic primary amines can not be prepared by Gabriel Phthalimide synthesis.
9) Alkyl amines are stronger bases than ammonia.
10) Aliphatic amines are stronger bases than aromatic amines.
11) B.P. of methyl amine is lower than that of methanol
12) Aniline does not undergo Friedel Craft alkylation reaction
13) Although -NH2 gr. Is –o & -p directing ,nitration of aniline give –m derivative alongwith –o
& -p derivatives.
14) Ethyl amine is soluble in water whereas aniline is insoluble.
15) Amines act as nucleophiles.
16) Gabriel phthalimide synthesis is preferred for synthesizing primary amines.
17) The C–N–C bond angle in trimethyl amine is 108°
18) The quaternary ammonium salts having four different alkyl groups are optically active
19) Alkylamines are more basic than ammonia
20) Aniline cannot be prepared by Gabriel phthalimide synthesis
21) Garbrielphthalimide synthesis is preferably used for synthesising primary amines.
22) Why is necessary to maintain the temperature between 273 K and 278 K during
diazotization ?
23) Why are amines basic in character?
24) Amides are more acidic than amines.
25) Why does silver chloride dissolve in aqueous methyl amine solution?
26) Aniline does not undergo Friedel Craft reaction.
27) Although amino group is o -and ρ-directing in aromatic electrophilic substitution
reactions, aniline on nitration gives a substantial amount of m-nitroaniline.
28) Ethylamine is soluble in water, whereas aniline is not.
NAMED REACTIONS
(i)
(ii)
(iii)
(iv)
(v)
(vi)
(vii)
(viii)
(ix)
Hofmann Bromamide reaction
Gabriel phthalimide synthesis.
Carbylmine reaction
Diazotization
Acetylation
Coupling reaction of diazonium salt
Gattermann reaction
Ammonolysis of alkyl halide
Write the name associated with the following reactions:
(a) RCONH2+Br2+4NaOHRNH2+Na2CO3+2NaBr+2H2O
(b) ArN2X- (CuCN/KCN)ArCN + N2
(c) RNH2+CHCl3+3KOH (heat)RNC+3KCl+3H2O
(d) ArN2X- (Cu/HCl) ArCl+N2+CuCl
CONVERSION
(i)
(ii)
(iii)
(iv)
(v)
(vi)
(vii)
(viii)
(ix)
(x)
(xi)
(xii)
(xiii)
(xiv)
(xv)
(xvi)
(xvii)
(xviii)
(xix)
(xx)
Benzene diazonium chloride to nitro benzene
Aniline to Benzene diazonium chloride
Ethylamide to methyl amine
Aniline to nitro benzene
Ethanamine to N-ethyl ethanamide
Chloroethane to propan-1-amin
Aniline to iodobenzene
Aniline to sulphanilic acid
Benzene to Aniline
Aniline to benzene
Ethanoic acid to ethanamine
p-toluidine to 2-bromo-4-methylaniline.
Methylbromide to ethanamine
4-nitrotoluene to 2-bromobenzoic acid
Nitrobezene to benzoic acid
Benzyl chloride to 2- phenylethanamine
Aniline to benzyl alcohol
Aniline into flurobenzene
Aniline into ρ-bromo aniline
Aniline into 1, 3, 5-tribromobenzene.
DISTINGUISHING TEST
(i)
(ii)
(iii)
(iv)
(v)
Aniline & ethyl amine
Dimethyl amine & Trimethylamine
Methylamine & dimethylamine.
Aniline & N-methylaniline
Aniline & benzylamine
(vi)
(vii)
(viii)
(ix)
(x)
Aniline and N-ethyl aniline
N-methyl propan-2-amine and N-ethyl-N-methyl ethanamine
Methylamine and dimethylamine
Secondary and tertiary amines
Ethylamine and aniline
MECHANISM
1) Show the mechanism of acylation of ethanamine and write the IUPAC name of the
product formed.
WORD PROBLEMS
1) How can you convert an amide into an amine having one C less than the starting
compound?
(a)Name the reaction
(b)Give IUPAC name & structure of amine obtained by the above method if tha amide is
3-chlorbutanamide.
2) An organic compound (A) on treatment with NH3 followed by heating forms compound
(B) which on heating with Br2 and KOH forms a compound (C) having M.F.
(C6H7N).Give the structures of A,B and C.and write the reactions involved.
3) An organic compound A (C2H3N) is used as a solvent of choice for many organic
reactions because it is not reactive in mild acidic and basic conditions. Compound A on
treatment with Ni/H2 forms B. When B is treated with nitrous acid at 273K, ethanol is
obtained. When B is warmed with chloroform and NaOH, a foul smelling compound C
formed. Identify A, B and C.
4) An aromatic compound A on treatment with aqueous ammonia and heating forms
compound B which on heating with Br2 and KOH forms a compound C of molecular
formula C6H7N. Write the structures and IUPAC names of compounds A, B and C.
COMPLETE EQUATIONS
1)
(i)
(ii)
(iii)
(iv)
(v)
(vi)
(vii)
(viii)
(ix)
(x)
LiALH4/H2O
________________
RCONH2
>
C6H5N2Cl + H3PO2 + H2O →
C6H5NH2 + HNO2 →
C6H5N2Cl + CH3COCl →
C2H5NH2 + C6H5SO2Cl →
C2H5NH2 + HNO2 →
C6H5NH2 + CHCl3 + 3KOH →
CH3CH2Cl ( NaCN) A (red.Ni/H2)  B
C6H5 NH2 + Br2 (aq)
C6H5NH2 + HCl (aq) 
(xi)
CH3CONH2 ( NaOH + Br2) 
(xii) C6H5NH2 + CH3COCl (base) 
2) Complete & name the reaction.
(i)
RNH2 + CHCl3 + 3KOH →
(ii)
RCONH2+Br2+4NaOH →
OTHER IMPORTANT QUESTIONS
1) Write the equation in which iodide ion replaces the diazonium gr. in diazonium salt
2) (i) Arrange the following in an increasing order of basic strength in water
C6H5NH2, (C2H5)2NH ,(C2H5)3N & NH3
(ii) Arrange the following in an increasing order of basic strength in gas
Phase C2H5NH2, (C2H5)2NH ,(C2H5)3N & CH3NH2
3) Explain
(i)
Presence of base is needed in the ammonolysis of alkyl halide
(ii)
Aromatic primaryamines can not be prepared by GabrielPhthalimide synthesis.
4) In the following rearrange
(i) In an increasing order of basic strength
C6H5NH2, C6H5N(CH3)2 ,(C2H5)2NH and CH3NH2
(ii)
In a decreasing order of basic strength
Aniline , p-nitroaniline and p-toluidine
(iii) In an increasing order of pKb values
C2H5NH2 ,C6H5NHCH3,(C2H5)2NH and C6H5NH2
5) Rearrange in an increasing order of their basic strength.
C6H5NH2,C6H5N(CH3)2,(C6H5)2NH and CH3NH2
6) Arrange the following compounds in an increasing order of their solubility in water
C6H5NH2,(C2H5)2NH and C2H5NH2
7) Describe the Hinsberg’s test for identification of primary, secondary and tertiary amines.
Also write the chemical equations of the reactions involved.
8) Write chemical equations for the following reactions:
(i)
Reaction of ethanolicNH3 with C2H5Cl.
(ii)
Ammonolysis of benzyl chloride and reaction of amine so formed with two moles
of CH3Cl
9) Write structures and IUPAC names of
(i) The amide which gives propanamine by Hoffmann bromamidereaction.
(ii) The amine produced by the Hoffmann degradation of benzamide.
10) Arrange the following in decreasing order of their basic strength:
C6H5NH2, C2H5NH2, (C2H5)2NH, NH3
11) Arrange the following in the decreasing order of their basic strength in aqueous solutions:
CH3NH2,(CH3)2NH,(CH3)3N and NH3.
12) Identify A and B
(i) CH3CH2Cl + NaCN
 A (reduction Ni/H2) B
(ii) C6H5NH2 + NaNO2+HCl A ( C6H5NH2) OH-  B
Chapter : 14
(BIOMOLECULES)
4 MARKS
1 Mark Questions
1. What type of linkage holds together the monomers of DNA?
2. Except for vitamin B-12, all other vitamins of group B should be supplied regularly in
diet. Why?
3. Write two main functions of carbohydrate in plants.
4. Why are carbohydrates generally optically active?
5. Explain the amphoteric behaviour of amino acid.
6. What is the structural feature characterising reducing sugar?
7. What is meant by reducing sugars?
8. What are mono saccharides?
9. What happens when glucose is treated with Br2 water?
10. What are the expected products of hydrolysis of lactose?
11. Write the name of linkage joining two amino acids.
12. What are the products of hydrolysis of sucrose?
13. What type of linkage holds together the monomers of DNA?
14. What are the ultimate products of digestion of protein ?
15. The two strands in DNA are not identical but are complementary. Explain.
16. Write the structure of the product obtained when glucose is oxidized with nitric acid.
17. Write a reaction which shows that all the carbon atoms in glucose are linked in a straight
chain.
18. Of the two bases named below,which one is present in RNA and which one is present in
DNA
(i)
Thymine
(ii)
Uracil
19. Amino acid have high melting point and are soluble in water. Why?
20. Vitamin C is found in fruits and vegetables. It cannot be stored in our body. Why?
21. Write the chemical name of vitamin B12.
22. Write the Zwitter ion structure of glycine.
23. Glucose does not give 2,4 DNP test Why?
24. Why are carbohydrates generally optically active?
25. Differentiate between keratin and insulin?
2 , 3 Marks Questions
1. Name the two components of starch. How do they differ from each other structurally?
2. (a) What changes occur in nature of egg protein on boiling?
(b) Name the type of bonding which stabilizes α- helix structure in proteins.
3. Despite having a -CHO gr.
(a) Glucose does not give 2,4 –DNP test. What does this indicate?
(b) Draw the Haworth structure of α-D-(+) glucopyranose
(c) What is the significance of D & (+) here.
4. An optically active compound having M.F.C6H12O6 is found in two isomeric forms (A)
& (B) are dissolved in water they show the following equilibrium:
(A)
↔
Equilibrium Mixture
↔
(B)
0
0
111
52.2
19.20
(i) What are such isomers called?
(ii)
Can they be called enantiomers ? Justify your answer.
(iii) Draw the cyclic structure of isomer (A)
5. An optically active amino acid (A) can exist in 3 forms depending on the pH of the
medium.if the M.F. of (A) is C3H7NO2 write
(i)
Structure of compound (A) in aqueous medium. What are such ions called?
(ii)
In which medium will the cationic form of compound (A) exist?
(iii) In alkaline medium, towards which electrode will the compound (a) migrate in
electric field?
6. Define in relation to protein (i) peptide linkage (ii) denaturation.
7. List the reactions of glucose which can not be explained by its open structure.
8. What happens when D-glucose is treated with the following reagents:
(i)HI
(ii)Br2 water (iii)HNO3
9. How are vitamins classified? Mention the chief sources of vit.A & vit. C.
10. Describe with example (i) Glycosidic linkage (ii) peptide linkage.
11. Describe with reference to protein (i) Primary structure of Protein (ii)Denaturation.
12. List any four vitamins. Mention the chief sources & functions of two of them.
13. What are nucleic acids? Mention two of their important functions.
14. What are amino acids? On electrolysis in an acidic solution, the relevant anions migrate
towards the cathode while in alkaline solution they migrate towards the anode. Give
reason.
15. What are essential & non essential amino acids? Give one example of each type.
16. Mention the type of linkages responsible for formation of:
(i)Primary structure of protein (ii) cross linking of polypeptide chains
(iii)α- helix formation
(iv) β – sheet structure
17. When RNA is hydrolysed, there is no relationship among the quantity of different bases
formed. What does this fact suggest about the structure of RNA?
18. Name the four bases present in DNA. Which one of these is not present in RNA?
19. Name two fat soluble vitamins ,their sources & the diseases caused due to their
deficiency in diet.
20. What are (i) Invert sugar (ii) Poly peptide?
21. State what are the following & how they differ from each other.
(i)
Nucleotide (ii) Nucleoside
22. (a) What is the structural difference between a nucleoside & a nucleotide?
(b) The two strands in DNA are not identical but are complementary .Explain.
23. (a)Write the important structural difference between DNA & RNA?
( b )Mention the names of bases produced on hydrolysis of DNA.
24. Amino acids may be acidic ,alkaline , or neutral.How does this happens? What are
essential and non essential amino acids? Name one of each type.
25. Differentiate between fibrous protein and globular protein.What is meant by denaturation
of protein?
26. Explain the following:
(i)
Invert sugar (ii) poly peptides (iii) Denaturation of protein
27. Mention three such facts/ reactions about glucose which can not be explained by its open
chain structure .What is meant by pyranose structure of glucose?
28. (a) Give one reaction of D-glucose which can not be explained by its open chain
structure.
(b) Give one example of each for essential and non essential amino acids.
(c) Differentiate between keratin and insulin.
29. (a) Write the zwitter ion structure of glycine.
(b) What is meant by inversion of sugar
(c) Name the vitamin in each case whose deficiency causes :
(i) Nightblindness (ii) Poor coagulation of blood
30. (a) Give reasons: (i) glucose does not give 2,4-DNP test and Sciff’s test
(ii) Amino acids have high m.p. and are soluble in water.
(b) What is meant by the secondary structure of protein.
31. Mention three such properties of glucose which can not be explained by its open chain
structure.
32. What is essentially the difference between alpha form and beta form of Glucose?
33. Shanti, a domestic helper of Mrs. Anuradha, fainted while mopping the floor.mrs.
Anuradha immediately took her to a nearby hospital where she was diagnosed to be
severely anaemic.The doctor prescribed an iron rich diet and multivitamins supplement to
her. Mrs.Anuradha supported her financially to get the medicines. After a month, Shanti
was diagnosed to be normal.After reading the above passage,answer the following
questions:
(i)
What values are displayed by Mrs.Anuradha?
(ii)
Name the vitamin whose deficiency causes pernicious anaemia.
(iii) Give an example of water soluble vitamin.
34. What are vitamins? Deficiency of which vitamin causes:
(i)
pernicious anaemia (ii) convulsions
35. What happens when D-glucose is treated with the following:
(i)
HI (ii) Bromine water.
36. What are the products of hydrolysis of the following
(i)
(ii)
Lactose
A nucleotide from DNA containing thymine.
37. What is glycogen? How is it different from starch? How is starch structurally different
from cellulose?
38. (i) Which one of the following is a disaccharide : Starch, Maltose, Fructose, Glucose ?
(ii) What is the difference between fibrous protein and globular protein ?
(iii)
39. (i)
Write the name of vitamin whose deficiency causes bone deformities in children.
Deficiency of which vitamin causes night-blindness ?
(ii)
(iii)
Name the base that is found in nucleotide of RNA only.
Glucose on reaction with HI gives n-hexane. What does it suggest about the
structure of glucose ?
40. After watching a programme on TV about the adverse effects of junk food and soft drinks
on the health of school children, Sonali, a student of Class XII, discussed the issue with
the school principal. Principal immediately instructed the canteen contractor to replace
the fast food with the fibre and vitamins rich food like sprouts, salad, fruits etc. This
decision was welcomed by the parents and the students. After reading the above passage,
answer the following questions:
(a) What values are expressed by Sonali and the Principal of the school?
(b) Give two examples of water-soluble vitamins.
41. State difference between Globular and Fibrous protein ( any two)
42. State difference between Amylose and Amylopectin.
43. State difference between glycosidc linkage and hemiacetal linkage.
44. Describe what you understand by primary structure and secondary structure of proteins.
45. Name the chemical components which constitute nucleotides. Write any four functions
of nucleotides in a cell.
Chapter : 15
(Polymers)
3 marks
1 mark Questions
1.
2.
3.
4.
5.
6.
7.
8.
Name the monomers of Nylon-2-Nylon-6 polymer
Define polymerization.
What is the repeating structural unit in polythene polymer?
Give an example of elastomers.
Write the monomer unit of Dacron?
Based on molecular forces what type of polymers neoprene?
Explain the difference between Buna- S and Buna- N.
What is the primary structural feature necessary for a molecule to make it useful in a
condensation polymerisation reaction?
9. What are plasticizer? Give one example.
10. What is the difference two notations Nylon-6 & Nylon-6,6 ?
11. Is (-CH2-CH)-n a homopolymer or a copolymer?
I
12.
13.
14.
15.
C6H5
What is meant by coplymerisation?
What are biodegradable polymers?
Define the term, ‘homopolymerisation’ giving an example.
Is (-CH2-CH)-n a homopolymer or a copolymer?
I
Cl
16. Write the name and structure of monomer of nylon-6.
2, 3 Marks Questions
1. What is the repeating unit in the condensation polymer obtained by combining
HOOCCH2CH2COOH(succinic acid) and H2NCH2CH2NH2 (ethylene diamine).
2. Differentiate between condensation and addition polymerisations. Give one example each of
the resulting polymers.
3. Identify the four groups into which the polymers are classified on the basis of the magnitude of
intermolecular forces present in them. To which group or groups do polythene and Bakelite
belong?
4. Differentiate between thermoplastic and thermosetting polymers. Give one example of each.
5. What is biodegradable polymer? Give an example of a biodegradable aliphatic polyester.
6. Draw the structures of the monomers of the following materials:
(i) PVC (ii) Teflon (iii) Neoprene
7. Give one example each of
(i)
Addition polymers, (ii) condensation polymers, (iii) Copolymers.
8. Write the name and structure of the monomer of each of the following polymers:
(i) Nylon-6 (ii) Buna-S (iii)Bakelite
9. Arrange the following polymer in increasing order of intermolecular forces, Also classify them as
addition and condensation polymer: Nylon-6,6, neoprene ,PMMA and PVC
10. State difference between chain growth and step growth polymer with suitable examples?
11. Differentiate the following pair of polymers based on the property
mentioned against each.
a) Novolac & Bakelite (structure)
b) Buna-S & Terylene (intermolecular force of attraction)
12. Write the names of monomers & classify them as addition or condensation
polymers.
(a) Teflon (b) Bakelite (c) Natural rubber
13. (a)What is the role of Benzoyl peroxide in the polymerization of ethane?
(b)What are LDPE & HDPE? How are they prepared?
14. What are thermosetting & thermoplastic polymers? Give one example of
Each.
15. What is step growth polymerization? Explain the steps involved in the
process.
16. Differentiate between molecular structure & behaviour of thermoplastic &
Thermo setting polymers.Give one example of each type.
17. What are biodegradable polymers? Give an example of such polymer &
mention its uses.
18. Identify the four groups into which the polymers are classified on the basis
of the magnitude of intermolecular forces present in them.To which group
or groups do polythene and Bakelite belong?
19. (a)Identify aliphatic biodegradable polyester which is used in packaging
and orthopedic devices.
(i) Write its full form
(ii) Give the structures of monomers from which it is formed.
(iii) Show the formation of polymer
20. (a)Write a reaction involved in the preparation of a biodegradable polyester.
(b) Monomer unit of synthetic rubber (neoprene)
(c)One use of Nylon-6,6
21. (a)Give an example of synthetic rubber and mention its one example.
(b) Write the structures of monomers of Dacron
(c) Arrange the following in increasing order of their tensile strength.
Nylon 6 ,Buna-S ,Polythene
22. Mention two important uses of each
(i)
Bakelite
(ii)
Nylon – 6
(iii)
PVC
23. Name the subgroups into which polymers are classified on the basis of magnitude of
intermolecular forces.
24. Which polymer is obtained when free radical polymerization of chloroprene occurs? Write the
structure of polymer thus obtained.
25. What are addition polymers? How are the two types of addition polymers
different from each other? Give one example of each type.
26. Write the (i) structure and (ii) one use of each of the following polymers
(a) PVC
(b) Urea-formaldehyde resin
(c) Bakelite
27. What is a biodegradable polymer? Give an example of a biodegradable aliphatic polyester.
28. Explain the term ‘copolymerization’ and give two examples of copolymerization.
29. After the ban on plastic bags, students of one school decided to make the people aware of the
harmful effects of plastic bags on environment and Yamuna River. To make the awareness more
impactful, they organized rally by joining hands with other schools and distributed paper bags to
vegetable vendors, shopkeepers and departmental stores. All students pledged not to use
polythene bags in future to save Yamuna River. ' After reading the above passage, answer the
following questions :
(i)
What values are shown by the students ?
(ii)
What are biodegradable polymers ? Give one example.
(iii)
Is polythene a condensation or an addition polymer ?
30. Write the monomer & one use of the following:
(i) PVC (ii) Teflon
(iii) Natural rubber
Chapter 16
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
11.
12.
13.
14.
15.
16.
17.
18.
19.
(Chemistry in Everyday life)
3 marks
1 Mark Questions
Give one example of artificial sweetener used by diabetic patients.
Name a substance that can be used as an antiseptic as well as disinfectant.
What is meant by Broad Spectrum Antibiotics?
Write the name of an antacid which is often used as a medicine.
What are antiseptics? Give one example.
What is meant by ‘narrow spectrum antibiotics’ ?
Differentiate between disinfectants and antiseptics.
What is the cause of a feeling of depression in human beings?Name a drug which can be useful
in treating this depression.
What are food preservatives? Name one such substance.
What are artificial sweetening agents ?
What is tincture of iodine?
What are artificial sweetening agents? Give two examples.
What are biodegradable and non-biodegradable detergents? Give one example of each.
Name one medicine which can act both as analgesics and antipyretic.
Why do we require artificial sweetening agents?
How does aspirin help in the prevention of heart attack?
Why are detergents called soap less soap?
Which of the following is an antiseptic? 0.2% phenol, 1% phenol
Why is bithional added to soap?
2 , 3 Marks Questions
1. In order to wash clothes with water containing dissolved calcium bicarbonate, which
cleaning agent will you prefer & why, soap or synthetic detergent? Give one advantage of soap
over synthetic detergent.
2. Reasons:
b) Aspirin drug helps in prevention of heart attack.
c) Diabetic patients are advised to take artificial sweetener instead of natural
sweeteners.
d) Detergents are non biodegradable while soaps are biodegradable
3. Classify synthetic detergents giving an example in each case.
4. What are antihistamine ? Give two examples. Explain how they act on the
human body.
5. What are biodegradable & non biodegradable detergents? Give one
example of each class.
6. Mention one use of each:
a) Ranitidine b) Paracetamol c) Tincture of iodine
7. a) What is the problem with hard water for washing with soap?
b) Explain (i) Broad spectrum antibiotics (ii) non ionic detergents
8. Discuss the two ways in which drug prevent attachment of natural
substrate on active site of enzyme.
9. Explain with example:
a) cationic detergent b) Tranqulizers
10. (a) What are antihistamine? Give two examples. Explain how they act on the human
body . Give an example.
(b) Name a substance that can be used as an antiseptic as well as disinfectant.
11. What are antibiotics? Distinguish between narrow spectrum & broad spectrum
antibiotics. Classify the following into Bactericidal & Bacteriostatic antibiotics :
Tetracycline , Penicillin.
12. Explain with example:
a) Food preservatives b) Disinfectants c) Non - ionic detergent
13. Explain with example :
a) Enzymes
b) Sweetening agents c) cationic detergent.
14. Explain with example: Analgesic ,Disinfectants, Antacid, Antiseptic.
15. Reasons:
(i)
Soap do not do the cleansing in hard water.
(ii)
Synthetic detergents are preferred to soap in washing machine.
16. What are anionic detergents ?How are they prepared ?Write their two uses.
17. What are artificial sweetening agents ?Give two examples .Name the
sweetening agents used in the preparation of sweets for diabetic patient.
18. (a) Define the term chemotherapy.
(b)While antacid & antiallergic drugs interfere with the function of
histamine ,why do these not interfere with the function of each other.
19. Explain the following with one example :
(i)
Food Preservation (ii) Enzymes (iii) Detergents
20. What are analgesic drugs?How are they classified and when are they usually recommended for
use?
21. Explain with one suitable example
(i)
Cationic detergent
(ii)
Enzymes
(iii)
Anti fertility drugs
22. What are biodegradable and non biodegradable detergents? Give one example of each. Is there
any structural difference between the two.
23. (a) Justify the following:
(i)
Sleeping pills are recommended to patients suffering from sleeplessness but it is
not advisable to take them without consulting the doctor.
(ii)
Why do we require artificial sweetening agents?
(b)Write the composition of Dettol.
24. (a) Name a substance which can act as both:
(i) analgesic and antipyretics (ii) antiseptic and disinfectant
(b) Explain the following with suitable example:
(i)
Broad spectrum antibiotics
(ii)
Anionic detergents
25. Give one example of each
(e) An artificial sweetener whose use is limited to cold drink
(f) A non ionic detergent
(g) A pain reliever used for relief from severe pain like postoperative or pain due to
terminal cancer.
26. What is tincture of iodine and what is it used for?
27. . (i ) Why do soap not work in hard water?
(ii ) What are the main constituents of dettol?
(iii) How do antiseptics differ from disinfectant?
(iv) Synthetic detergents are better than soap.
28. (i) What class of drug is Ranitidine?
(ii ) If water contains dissolved Ca2+ ions, out of soaps and synthetic detergents,which
will you use for cleaning clothes?
(iii ) Which of the following is an antiseptic?
29. (i)
(ii)
0.2 % phenol or 1% phenol
Give two examples of macromolecules that are chosen as drug targets.
What are antiseptics ? Give an example.
(iii)
Why is use of aspartame limited to cold foods and soft drinks ?
30. Mr. Roy, the principal of one reputed school organized a seminar in which he invited parents
and principals to discuss the serious issue of diabetes and depression in students. They all
resolved this issue by strictly banning the junk food in schools and to introduce healthy snacks
and drinks like soup, lassi, milk etc. in school canteens. They also decided to make compulsory
half an hour physical activities for the students in the morning assembly daily. After six months,
Mr. Roy conducted the health survey in most of the schools and discovered a tremendous
improvement in the health of students.
After reading the above passage, answer the following :
(i)
What are the values (at least two) displayed by Mr. Roy ?
(ii)
As a student, how can you spread awareness about this issue ?
(iii)
What are tranquilizers ? Give an example.
(iv)
Why is use of aspartame limited to cold foods and drinks ?
31. (a) Which one of the following is a food preservative?
Equanil, Morphine, Sodium benzoate
(b) Why is bithional added to soap?
(c) Which class of drugs is used in sleeping pills?
32. Why do soaps not function in hard water, for washing clothes? How are synthetic detergents
better than soaps for this purpose?
33. How do antiseptics differ from disinfectants? Give one example of each type.
34. (a)What class of drug is Ranitidine ?
(b) What type of analgesics are chiefly used for the relief of pains of terminal cancer.
35. State reasons for the following occurrences:
(i) Soaps do not do the cleansing in hard water.
(ii) Synthetic detergents are preferred to soaps in washing machines
36. What are the following substances? Give one example of each type.
37. (i) Tranquilizer (ii)antihistamines (iii) antifertility drugs
38. How antifertility drug differ from MTP.Explain with suitable examples.
39. Why do drug designed to cure some ailments in one organ in the body not affect the other
parts? Explain with examples.
40. What are biodegradable and non-biodegradable detergents? Give one example of each type.
VALUE BASED QUESTIONS WITH ANSWERS
1. THE SOLID STATE
1. In India, we have shortage of electricity. Electricity is being produced by hydel power, thermal
power, gas power, nuclear power, etc. which need a lot of fuel which is limited in our country.
Non-conventional sources like wind energy, tidal energy, solar energy is being used to some
extent to generate power. Solar energy can be converted into electricity by special type of
substances called photovoltaic material. Use of CFL and LED lamps can also save lot of
electricity.
(i) Name one photovoltaic material.
(ii) Why is solar power generation better than conventional way of generating power ? Give one
reason.
(iii) Why is solar power not very popular in India ?
(iv) What are the values associated with above passage ?
2. A large variety of solid state materials have been prepared by combination of group 13 and 15
or group 12 and 16 to stimulate average valence of four as in Ge or Si. InSb, AlP, GaAs are
group 13-15 compounds. Gallium arsenide semiconductors have very fast response and have
revolutionised the design of semiconductor device. ZnS, CdS, CdSe, HgTe are examples of
group 12-16 compounds. On adding
calculated amount of impurity to silicon and germanium, increases their conductance.
(i) Why are the compounds of group 12-16, 13-15 better semiconductors than silicon and
germanium ?
(ii) Are these compounds safe to use for environment ?
(iii) What is the best solution to the problem ?
(iv) What are the values associated with it ?
3. The conductance of metals decreases with increase in temperature and increases with decrease
in temperature. Some metals offer no resistance at low temperature. These are best for electrical
transmission.
(i) What is the name given to metals which practically offer no resistance at low temperature ? In
Japan, fastest train makes use of these substances.
(ii) Are superconductors diamagnetic or paramagnetic ?
(iii) How does the use of superconductors for electrical transmission helps in economy of a
country ?
4. Graphite has typical hexagonal structure. Carbon atoms are arranged in different layers and it
is soft and slippery. It is used in pencils, dry cells and other cells.
(i) Why is graphite used as lubricant at high temperature in machine parts ?
(ii) Why is graphite good conductor of electricity although it is covalent solid ?
(iii) Is use of graphite threat to environment ?
5. Heart failure patients, who are too weak for a human transplant, might move a step closer to
gaining access to the first fully self-contained implanted artificial heart. The artificial heart
consists of a titanium and plastic pump, an implanted microprocessing ‘brain’ that monitors and
controls blood flow and an implanted charged battery. An external power unit transmits
electricity through the skin to the device implanted above the ribcage. The unit can draw power
from portable batteries. Titanium is also used in dental implants.
(i) Why is titanium used in making artificial heart ?
(ii) What is the use of artificial heart implant ?
(iii) What advice will you give to people to prevent heart ailments ?
ANSWERS
1. (i) Amorphous silica
(ii) Conventional way needs a lot of fuel and creates pollution.
(iii) It is because it requires a lot of initial cost and maintenance cost of batteries.
(iv) We should conserve electricity by switching OFF electrical appliances whenever not in use
andmake use of non-conventional sources of energy.
2. (i) It is because the bonds in these compounds are not perfectly covalent and the ionic
characterdepends upon the electronegativities of the two elements.
(ii) No, these compounds contain heavier metals which are poisonous.
(iii) Si and Ge doped with group 13 and 15 elements can serve the purpose.
(iv) Team work and cooperation give better results.
3. (i) Superconductors
(ii) Diamagnetic
(iii) Lot of electricity is wasted due to resistance of metals like aluminium. Superconductors
practically offer no resistance, therefore, efficiency of transmission will increase and save a lot of
money, improving economy of a country.
4. (i) It is because it is soft and slippery and has high melting point.
(ii) It is due to the fact that in different layers each carbon is covalently bonded to three atoms in
the
same layer. The fourth electron is free to move.
(iii) No, its use is safe for environment.
5. (i) It does not get corroded, conductor of electricity and biocompliant solid for surgical
implants.
(ii) Crores of people in the world have heart too weak to satisfy the body’s demand for blood.
Most
severe cases could benefit from a transplant.
(iii) Less intake of sugar, salt, trans-fats, saturated fats, regular exercise and medical check-up.
2. SOLUTIONS
1.
A sea driver was facing problems while deep into the water though he was carrying air
tank along with. He was feeling discomfort and pain in breathing while ascending. He consulted
a dictor who advised him to carry a tank containing a mixture of helium(11.7%), nitrogen(56.2%)
and oxygen(32.1%) in place or air. On doing so, his problem was solved and he no longer felt this
problem, Read the above narration and answer the following questions:
a. Why was sea diver facing discomfort while breathing?
b. How did doctor help him?
c. What is the value associated with the advice given by the doctor?
Ans. (a) Deep down the sea, the pressure is high. While ascending the pressure gets
reduced. As a result, the solubility of nitrogen in water decreases. It is released as bubbles
and causes discomfort to the driver.
(b) The presence of helium reduces the concentration of nitrogen. Therefore, lesser
bubbles are released and this causes less pain or discomfort to the sea diver.
(c) Doctor has diagnosed the problem correctly. Any discomfort in breathing is likely to
affect the lungs and will be ultimately very harmful. Doctor has indeed done a valuable
service to the sea driver.
2. A doctor advised a patient suffering from high blood pressure to take less quantity of
the salt.
a. What is the role of salt in increasing blood pressure?
b. How does low intake of salt help in reducing the blood pressure?
c. What is the value associated with this?
Ans.(a) The body fluid already conatins Na+ and Cl- ions. Higher in take of the salt
further increases their concentration as well as osmotic pressure. The blood pressure of
the patient is also likely to increase. As a result, there is inflow of water in the cells which
causes the retention of water in the tissue cells. This leads to swelling in the face, legs
and also in the other parts of the body, this is called edima.
(b) Low intake of salt reduces the osmotic pressure as well as blood pressure of the
patient.
(c) Persons suffering from high blood pressure or hypertension must be very careful
about their diet. They should control intake of salt. This is even more necessary in cold
climate where we perspire very little.
3. Scuba-divers must cope with high concentrations of dissolved gases while breathing
air at high pressure underwater. Increased pressure increases the solubility of the
atmospheric gases in blood. When the divers come to the surface, the pressure decreases.
This releases dissolved gases and leads to formation of bubbles of nitrogen in blood. This
blocks the capillaries and creates medical conditions known as bends, which are painful
and dangerous to life. Oxygen level is less at higher altitudes.
(i) How can you save life of scuba divers?
(ii) Why are aquatic animals more comfortable in cold water rather than in warm water?
(iii) What is effect of temp? on solubility of gases?
(iv) The climbers to high altitude have low blood oxygen which makes them weak and
unable to think clearly. What is the condition known as?
(v) How can we solve problem of Anoxia?
(vi) What is the shape of the graph if we plot mole fraction of O2 gas in water versus
partial pressure of oxygen?
Ans: (i) We can save their life by adding less soluble gases like He to O2 in oxygen
cylinder.
(ii) Aquatic animals are comfortable in cold water because of high content of dissolved
oxygen in cold water.
(iii) As temperature increases, solubility of gases decreases.
(iv) This is because at higher altitudes, atmospheric pressure is low. This condition is
known as Anoxia.
(v) We can avoid this problem by carrying cylinders of pure oxygen gas.
4. Two solutions having same osmotic pressure at a given temp. Are called isotonic
solutions. The osmotic pressure associated with fluid inside blood cell is equivalent to
that of 0.9 %( w/V).
(i) What precautions should be taken when saline is given intravenously to patients by
doctors?
(ii) If saline has concentration more or less than 0.9%, what should be done and why?
(iii) What will happen to a hypertonic solution is injected to our body? What is the
solution of this problem?
(iv) What will happen if hypotonic solution is injected to our body?
(v) What is meant by 0.9 %( w/V) saline solution?
Ans: (i) We should first confirm that the saline is isotonic to blood. i.e. 0.9 %( w/V)
(ii) It shouldn’t be injected intravenously.
(iii) It will shrink blood cells by taking the water content of the cell out. We can either
drink water or inject a hypotonic solution into blood.
(iv) If hypotonic solution is added, then the blood cells will oblate and burst.
(v) A solution which contains 0.9 g of solute in 100 ml of solution is referred to as 0.9%(
w/V).
5. We have many types of water purifiers. Zero-B is based on disinfecting properties of
iodine. UV purifier is based on killing bacteria by UV light. These R.O. purifiers are
being used.
(i) What is the full form of R.O. purifier?
(ii) What is the function of porous membrane?
(iii) Which method of purification is more economical for countries using sea water, flash
distillation or R.O. for getting potable water? Why?
(iv) What is the material used for making membrane?
(v) If none of the purifier is available, what is the best way of purifying water?
Ans: (i) Reverse Osmosis
(ii) Porous Membrane allows easy osmosis of water from region of low conc. of salt to
high conc.
(iii) R.O. is a better substitute because in distillation process, a large amount of heat is
required in the boiling process, whereas in R.O., only osmosis takes place.
(iv) Cellulose Acetate is used.
(v) We can purify water by Alum, or use the traditional method of purification where we
pass water through layers of pebbles, sand, charcoal etc.
6. A raw mango in conc. salt solution loses water via osmosis and shrivels into pickle.
Wilted flowers survive when placed in fresh water. A carrot becomes limp because of
water loss into atmosphere can be placed into osmosis. Those people who take lot of salt,
it is harmful for them. The preservation of meat is done by salting and of fruits by adding
sugar against bacterial action.
(i) Why is intake of more salt harmful for people?
(ii) What is Oedema? How is it caused?
Ans: (i) Intake of excess salt cause water retention in tissue cells and intercellular spaces
due to osmosis. This causes swelling or puffiness.
(ii) This above explained phenomena of swelling of tissue cells due to osmosis is called
Oedema. This is caused by excess intake of salt.
7. Water is used as a coolant in vehicles. In cars, ethylene glycol is used as a coolant. In
cold countries, water gets frozen so it can’t act as a coolant. Ethylene glycol is added to
water so that its freezing point is lowered and it does not freeze. At hill station, snowfall
takes place. Clearing the snow from the road is essential for smooth running of traffic.
(i) What is the role of ethylene glycol added to water?
(ii) Why does sprinkling of salt help in clearing snow covered roads in hilly areas?
Explain the phenomenon involved in the process.
(iii) How is life of people affected by snowfall?
Ans: (i) Ethylene Glycol is added to water because it reduces the freezing point of water.
This prevents freezing of water in extreme cold conditions.
(ii) Sprinkling of salt reduces the fusion temperature of salt further, because of the
increase in the no. of particles. This causes ice to melt easily. The phenomenon is called
‘Depression in Freezing Point’.
(iii) Due to snowfall, roads get covered with snow hindering transportation. In water
tanks, car radiators etc. water might freeze. Because of this anomalous expansion during
freezing of water, radiators may burst. We use anti-depressants in such cases.
8. You are staying near a fertilizer factory. In the middle of the night there is a leackage
of ammonia which is detected by its smell. Within 10 minutes you find the smell is
intolerable.
a.
What do you do as first aid against this gas spill accident for self and neighbour ?
b.
What value do you derive from this ?
Ans.Ammonia highly soluble in water .It is detected by its characteristic fishy odor.
Hence keep a wet kerchief on your nose to stop inhaling the gas .Then help your
neighbours with your suggestions.
b.Alertness to tackle disaster for society .
9. The chairman, kandla (Gujarat )port due to water scarcity has decided to desalinate
sea water to obtain potable water.
a. As a student of chemistry which method will be suited to use ?
b. Discuss the method .
c. What value have you inculcated in using this method ?
Ans.
a. Reverse osmosis .
b. Discussed
c. Using less energy i.e. energy conservation
OR
a.Desalination using evaporation using sun’s energy
b. Discussed
c. Using renewable source of energy.
10.Bharath went to his grandfather’s house in winter this year. As usual he went for
fishing .His grand mother told him ther will be no fishes in the lake . He noticed that it
was more difficult to find fishes in winter .The fishes wre deep inside the river . Whereas
in summer they were on the surface and hence he was able to catch fishes .
a.
Why are the fishes on the surface in the water than in the depth in summer ?
b.
What value can be derived from this?
Ans.
a.
According to the Henry’s law at low temperature gases are more soluble and
hence as more oxygen gets dissolved in water fishes survive better even in the depth of
river . In the summer as the oxygen is less in water the fishes come to the surface.
b.
The value that I derive from this is wisdom is superior to knowledge .
11. Srisha wanted to keep ice creams without melting .so he had to keep it on ice taken in
the container .his grand mother advised him to pour salt on the ice.
a.
Why?
b.
What is value in this?
Ans.
a.
Adding salt to ice decreaces the melting point of the ice .Hence the decrease in the
temperature of the ice
b.
Obey the elders.
12. An untrained nurse used distilled water and not saline water while giving injection to
the patient. Immediate swelling was noticed in the area where the injection was given.
What mistake was committed by the nurse? Which precaution she must take in future?
Ans. Ordinary water or distilled water is hypotonic as compared to blood cells which are
hypertonic. When injection to administer in ordinary water, there is immediate flow of
excessive fluid into cell membrane and swelling occurs. In saline water (0.91% of NaCl
solution) which is isotonic with RBCs, no flow of extra fluid would occur and no
swelling would be noticed in this case. In future saline water must be used for giving
injection.
13.Intravenous injections are always dissolved in water containing salts at particular ionic
concentrations that match blood plasma concentration.
(a)
What name is given to solution described above?
(b)
What is the name of solution having concentration higher than body fluid?
(c)
What name is given to solution having concentration less than body fluids?
(d)
Why do doctors advice to do saline gargles in case of sure throat?
(e)
What values are possessed by doctors who use isotonic solutions in nitrogenous
injections?
Ans.
(a)
Isotonic solution
(b)
Hypertonic solution
(c)
Hypotonic solution
(d)
It gives relief as common salt is antiviral agent. It is hypertonic solution and helps to take
out fluids from the throat.
(e)
These doctors save people from ill effects of hypertonic and hypotonic solutions.
14.You are staying near a fertilizer factory. In the middle of the night there is a leackage
of ammonia which is detected by its smell. Within 10 minutes you find the smell is
intolerable.
c.
d.
Ans.
What do you do as first aid against this gas spill accident for self and neighbour ?
What value do you derive from this ?
e.
Ammonia highly soluble in water .It is detected by its characteristic fishy odor. Hence
keep a wet kerchief on your nose to stop inhaling the gas .Then help your neighbours with your
suggestions.
f.
Alertness to tackle disaster for society .
3. ELECTROCHEMISTRY
Q.1. People are advised to limit the use of fossil fuels resulting in Green House Effect leading
to a rise in the temperature of earth. Hydrogen provides an ideal alternative and its combustion in
fuel cells.
a. Write electrode reaction in H2-O2 fuel cell.
b. How is green house effect reduced by the use of fuel cells?
c. Write the values associated with preference of using fuel cells to fossil fuel.
Q.2
In Apollo Space programs, hydrogen-oxygen fuel cell was used.
(a) Explain why, fuel cell is preferred in space programme.?
(b) Mention the values associated with the decision of using fuel cell?
Q.3
Ira a student of science went with her grandfather to buy a battery for their inverter and
camera. They found two types of batteries, one a lead storage battery and other a NickelCadmium storage battery. Later was more expensive but lighter in weight. Ira insisted to
purchase costlier Nickels-Cadmium battery.
(a)
In your opinion, why Ira insisted for Nickel-Cadmium battery? Give reasons
(b)
Write the values associated with above decision?
Q.4
Shyam's father wants to buy a new car. In the market various options are available.
Shyam persuades his father to buy a hybrid car which can run both on electricity as well as on
petrol.
a.
Mention the values associated with this decision.
b.
Name the battery used for running the car.
c.
Write the reactions taking place at the anode and cathode of battery.
Q.5
Reema the student of class XII Science suggested her father to place a pouch of silica gel
in the opening of iron pipes when he was preparing a shed for parking his car?
a.
How does Reema apply the knowledge of chemistry?
b.
What value was associated with this decision?
c.
How she shows the concern to society?
Ans.
1. a. Cathode: O2 (g) + 2H2O (I) + 4e-→ 4OH-(aq)
Anode: 2H2 (g) + 4OH-(aq) → 4H2O (I) + 4eb. no any pollutant is being formed as product of cell reaction.
c. Environmental conservation
2. a. No any pollutant is formed only water is formed which is used for drinking purpose.
b. Environmental conservation
3. a. Pollution free, No poisoning of lead as in lead storage battery.
b Environmental conservation, Concern for workers associated with lead storage battery
repairment.
4. a Environmental conservation, Energy Conservation
b. Lead Storage Battery
c. Anode: Pb(s) + SO42- (aq) → PbSO4(s) + 2e—
Cathode: PbO2(s) + SO42-(aq) + 4H+ (aq) + 2e-→ PbSO4 (s) + 2H2O (I)
5. I. Silica gel is a good adsorbent therefore prevent from rusting.
ii. Knowledge is useful when it is put in practice.
iii. She shows her concern to the environment.
4. CHEMICAL KINETICS
1. One day in the class, Rohit learnt that conversion of diamond to graphite is energetically
favoured. He felt very concerned about it. If it was likely to happen, then it will cause a lot of
financial loss to those people who have diamonds because their diamonds will be ultimately
converted to graphite which will be of no value. He discussed it with the teacher. His teacher
told him that it was unlikely to happen, though it was thermodynamically favourable.
a.
In your opinion why it is not possible for a diamond to get converted into graphite
through process is energetically favourable?
b.
How do you relate these observations to values of daily life?
Answer. a.
Although the conversion of diamond into graphite is energetically favourable
yet it is unlikely to occur due to occurrence of very large activation energy barrier for this
process to occur.
b.
In day to day life, we find that sometimes it seems that is chaos, gloominess, dishonesty
and crookedness everywhere but there are incidents which provide us moral courage to
overcome to these negative forces and help us for positive thinking, happiness and wellbeing.
We strive with greater efforts to create an atmosphere of honesty, responsibility, support,
commitment, perseverance and achieve new heights of success.
2. A catalyst is a substance which increases the rate of a reaction without undergoing any change
in itself. A small amount of the catalyst is sufficient to bring large change in the rate of a
reaction. It takes part in the reaction but is regenerated at the end of the reaction.
a.
How does a catalyst increases the rate of a reaction?
b.
In society how do catalytic elements play their role in strengthening or weakening the
social value?
Answer. a.
A catalyst increases the rate of a reaction by lowering the potential energy
barrier and providing a alternate path which requires less activation energy.
b.
In our society we find certain people to act as catalysts in certain incidents. Sometimes
we find that person who has negative thinking and does not like peaceful atmosphere, add fuel
to the fire whenever there is a clash between two groups of people. He provokes indirectly one
group of people against the other. At the same time there are people who like peace and
harmony in the society. Even if there is a little problem in the people in society, they try to sub
side the issues by their understanding and goodwill.
3. Coal does not burn by itself in air but once initiated by flame, it continues to burn. In our
surroundings we can observe many processes in day to day life of such type. It is blissful to
existence of life on earth otherwise there would have been a great harm to civilisation as fuels
would have burnt by themselves and explosives could not be stored safely.
a.
What reason do you assign for non-occurrence of such processes at room temperature?
b.
How do you find values linked with such processes?
Answer. a.
The reason for non-occurrence of such processes is the existence of activation
energy barrier. The occurrence of such process requires a very high activation energy which is
not available at room temperature.
c. Our society is facing a lot of problems which are major hurdles in our progress. People have
innovative ideas to solve such problems. Lack of proper atmosphere, infrastructure and
orientation hinders their ideas. When they get proper channel and platform they exploit their
ideas to get rid of evils facing our society. Once the process starts, other people come forward
with innovative ideas and this is how progress begins which achieves greater heights resulting in
upliftment of society.
5. SURFACE CHEMISTRY
1.While returning from school, Anurag witnesses an accident on road. A young man had
Suffered injuries due to skidding of his bike. Anurag rushed to the aid of the young man
Along with some more people. While some people took the young man to a nearbyhospital,
Anurag tried to find out the reason behind skidding of the bike. He found out that The bike
skidded due to oil spilled on road. He then arranged for an old cloth and wiped the oil from
road.
(I)Mention the value shown by the student in the above case.
(ii)What other way can be employed to remove the oil other than wiping with a cloth?
Explain the mechanism.
Ans. (i) Values: social responsibility, empathy.
(ii) The oil spill on the road can also be removed by washing it with soap solution.
Soap molecule form micelles around oil molecule and thus gets removed
2.
On visit to your native village, you find that lot of smoke, dust and some other gases are coming
out of the chimney of a recently set up factory near the village.
Answer the following questions:
(i) As a chemistry student, what method you will suggest the factory owner to manage dust and
smoke?
(ii) What is the basic principle involved in your suggestion?
(iii) What values are associated with your advice?
Ans.2 (i) The dust and smoke coming out of chimney can be controlled by installing Cottrell
smoke precipitator.
(ii) Cottrell precipitator consist of two metal discs charged to a high electrical potential. The
charge on colloidal dust and carbon particles of smoke is neutralised and they get precipitated
while free gases escape out of chimney.
(iii) The knowledge of Cottrell precipitator and management of dust and carbon particles of
smoke can help us to clean our environment and make it healthier.
3. A number of industries make use of the phenomenon of adsorption,
e.g., Instrumentation
industry, dyeing Industry, paint industry, coal
Now answer the following questions:
mines etc.
(i)
You might have seen that a small packet containing some material packed in a piece of
cloth or tissue paper Is placed in delicate
instruments, e.g., along with the strips used for
testing blood sugar. What does it contain and why?
(ii)
When a worker goes deep into a coal mine, how does he protect
poisonous gases present there?
himself
from
the
(iii)
What do the paint manufactures add in the paints so that It has a good
covering
power on the furniture doors, windows or the wall? Further,
In spirit polish of wooden
surfaces, it is first cleaned with spirit. Why?
(iv)
When you give your clothes for dyeing, the dyer adds a substance called mordant before
dye. Why?
Ans:- (i) Some delicate instruments are sensitive to moisture. The packet place inside contains
a dehumidizer (usually silica gel) which adsorbs
the moistre of the air present around it.
(ii)
The worker wears a gas mask which contains suitable adsorbents so
that poisonous
gases present in the mine are preferentially adsorbs and
the air for breathing is purified.
(iii)
Manufactures add adsorbents to the paints so that all dissolved gases
in the paint
are adsorbed as otherwise, they will form gas bubbles
which will later burst. All wooden
surfaces are cleaned with spirit to
remove adsorbed layers of gas, liquid or solid film.
(iv)
Mordant adsorbs the dye uniformly as otherwise uneven dying would
take place.
4. The phenomenon of adsorption finds a number of useful application in
chemical
laboratory,
e.g. in the separation of mixture of compounds,
use of dyes as indicator in certain titrations, in
the preparation of water similar to distilled water required for the preparation of solutions, e.g
that of silver nitrate which otherwise gives while
precipitate with ordinary water. It has also
helped in the conservation of water in countries where there is scarcity of water.
Now, answer the following questions:
(i)
How does adsorption help in the separation of components of a
compounds?
(ii)
How does adsorption help In the titration of KBr with AgNO3
mixture
solution?
of
(iii)
How does adsorption help in the preparation of water of the same standard as that as
that of distilled water?
(iv)
How does adsorption help in the conservation of water in countries
where there is scarcity of water during summer?
ike
Australia
Ans:-(i)The selective adsorption by selective adsorbent has helped to developed a technique for
separation of components of mixture
(ii)
It is a precipitation titration. The dye eosin is added as indicator. The
colour of the
dye is adsorbed on the particles of AgBr, and desorbed at the end point. That is why such dyes
are said to act as `adsorption indicators`.
(iii)
Ordinary water is repeatedly passed through ion exchanges which adsorb all the cations
and anions of the salts present in water.
(iv)
A layer of stearic acid is sprayed over the lakes and other water
adsorbed on the surface and protects the water from evaporation.
5.
(i)
reservoirs.
It
is
In a number of cases, particles of substances are found to exist in a
size which is neither too
small nor too large. They are too small to settle down but large enough to scatter light, e.g., dust
particles in a
room. These particles are called colloidal particles. Further, they are
found
to carry charge. These characteristics of colloidal particles make them useful in our everyday life.
Now, answer the following questions:
Why a number of medicines available in the market are in the
colloidal form?
(ii)
If there are clouds in the sky but they are not showering rain, how can
artificial rain?
we bring about
(iii)
When there is a cut and it is bleeding, we apply alum to stop bleeding.
work?
How does it
Ans:-(i) Medicines in colloidal form are more easily assimilated and hence,
effective. This is because in the colloidal form, hey have large surface area.
are
(iv)
How the property of colloidal particles not to settle down is made use
of in warfare ?
more
(ii)
Clouds are colloidal particles of water suspende din the air. As
collidal particles carry
charge, they can be coagulated to form bigger
drops by spraying oppositely charged
colloidal dust or sand particles
over them or by throwing common salt as it is an
electrolyte and
brings about coagulation of water particles.
(iii)
Alum is an electrolyte which brings about the coagulation of the colloidal particles of
blood (albuminoids), thereby forming a clot. s a
result, bleeding stops.
(iv)
In warfare, smoke screens are used which are nothing but
substances (e.g., Sic14or titanium
oxide) in the air.
6.
colloidal dispersion of certain
When two immiscible liquids are shaken to form a nearly
homogeneous mixture, it is
called an emulsion. We use a number of
emulsion in everyday life. Digestion of fats in our
intestines also takes
place through emulsification. Emulsions have sometimes harmful
effects too. Now, answer the following questions:
(i)
Give one example of an emulsion which we use in our everyday life
What are Its constituents ?
for our health.
(iii)
How is that water alone does not remove oily or greasy spots from our
soap solution does it?
clothes
(ii)
How fats are digested in the intestines?
(iv)
Give one example where formation of emulsion is harmful.
but
Ans:-(i) Milk. It is an emulsion of liquid fats in water.
(ii) the digestion of fats in the intestine takes place by the process of emulsification.
A small amount of fat reacts with alkaline solution present in intestine to form a sodium
soap.This soap causes the emulsification of the of the fat thereby making metabolic processes
easy.
(iii) soap acts as an emulsifying agent and helps in the formation of
oil-in-water which is washed away with water .
emulsion of
(iv) Petroleum forms emulsion with water which is harmful when we need only petroleum
likewise in the areas where small amount of petroleum is present the well water becomes unfit
for drinking.
7. Milk and Cold cream are the examples of colloidal system. Which
type of colloid are they? Can we dilute them by adding water? Mrs.Nainy being student
of chemistry brought the samples of Milk and Cold cream and tried to dilute them and
performed experiment before writing answer. Why did she do so is there any value do
you find here.
Ans---Milk and cold cream are liquid in liquid colloids i.e. ; emulsion.
She wants to identify the types of emulsions i.e. oil in water or water in oil by dilution.
Milk is diluted on addition of water.So it is oil in water emulsion
But cold cream does not dilute by addition of water. So it is water in oil emulsion
Value: Persons who are stif or rigid do not mix up well with others but those who are
friendly and flexible can easily mix up with others like milk. So we should be flexible.
6. GENERAL PRINCIPLES AND PROCESSES OF ISOLATION OF ELEMENTS
Q1. Iron is much abundant in the earth’s crust than Aluminium. Both these metals are
extensively used as structural materials. Over a period of time, iron creates problems but
Aluminium does not. Now answer the following questions:
(i) Give the one principal ore of each iron and aluminium.
(ii) How is iron and aluminium obtained from their respective ores?
(iii) What is the cause of problem with iron but not with aluminium? How can this problem
be overcome?
A1.(i) The principal ore of iron is haematite (Fe2O3) while that of aluminium is bauxite(Al2O3)
(ii) Iron is obtained by reduction of purified Fe2O3 with coke in blast furnace while
aluminium is obtained by electrolysis of purified Al2O3 to which cryolite(Na3AlF6) and
fluorspar (CaF2) have been added.
Q2. Many methods are available for refining of metals. These depend upon the nature of the
Metal or the use to which they are supposed to put. One such method is electrolytic refining.
Besides refining of metals, this method also forms the basis of electroplating which not only
gives decorative look to the articles but also protects them from corrosion.
Now answer the following questions:
(i) Name few metals which are refined by electro refining?
(ii) Comment upon the principle of electrolytic refining.
(iii) Give two uses of electroplating.
A2.(i) Cu, Ag, Au, Pb, Ni, Cr etc.
(ii) In electro refining of metals, the impure metal is madeup of anode while cathode is
made up of pure metal. these electrodes are suspended in an electrolyte which is the
solution of a salt of the metal to be purified. On passing electric current the following
reaction take place.
Anode:M(s)
M(aq)m+ + nen+
Cathode:-M (aq) + ne
M(s)
The impurities settle down under the anode as anode mud.
(iii) Iron is protected from rusting by electro plating it with metals like Ni, Cr, Sn, Zn etc.
Since Zn is the cheapest among these metals it is usually coated on iron sheets and the
process is called galvanization
Similarly articles made of iron, copper, brass etc. are decorated by electro plating with
silver and gold to enhance their beauty
Q3.
Carbon monoxide is used for refining of impure nickel in the Monds process. But
Carbon monoxide is a highly poisonous gas inhalation of which causes death.
Now answer the following questions:
(i) What is the principle of Monds process for refining of nickel?
(ii) How does carbon monoxide poisoning cause death?
(iii) Should Monds process for refining of nickel be banned because carbon monoxide
not only pollutes the environment but its accidental leakage from the plant may
prove fatal for workers in the factory?
A3. (i) When impure nickel is heated in a current of CO at 330-350 K, it forms volatile nickel
tetracarbonyl complex leaving behind the impurities. The complex thus obtained is
heated to a higher temperature (450-470 K) when it undergoes decomposition giving
pure nickel and releasing CO.
(ii) Carbon monoxide us highly poisonous. It combines with haemoglobin of the blood to
formcarboxyhaemoglobin.
Haemoglobin + CO
Carboxyhaemoglobin
which is about 300 times more stable than the oxyhaemoglobin complex which it forms
with oxygen.
Haemoglobin + O2
Oxyhaemoglobin
This prevents haemoglobin present in the blood cells from carrying oxygen from the
lungs to all parts of the body causing suffocation leading to death
(iii) Although CO is an environmental pollutant and a threat to the life of workers in the
factories, but it being very cheap it keeps he cost of pure nickel low which is
extensively used in nickel plating and other articles of daily use. Therefore Monds
process cannot be banned if we have to keep the pure nickel metal cheap to meet the
requirements of the industry. Instead better safety arrangements should be made for the
workers in the factory.Further, if the cost of electricity is reduced, electrolytic method
for refining of impure nickel metal can be used.
7. P Block Elements
1. A man with a bag on his shoulder was moving on the road of a village . He offered a chance to
the villagers of cleaning and polishing their jewellery ata cheap cost. A large crowd got
interested to cash that opportunity. The man used a magic liquid in which when gold ornament
dipped it becomes more shinyand after some time when that man finished his work and
returned, a womasn shouted and complained that her gold chain reduced to half on cleaning .
What was the reason behind that?
Answer—The magic liquid used by that man was AQUA REGIA which is a mixture of con.HNO3
and con.HCl in a ratio of 1:3act as solvent for noble metals like gold.
2. Sulphuric acid is manufactured by contact process. During the process the following reactions
takes place
2 0 ( ) + ( ) ⇌2 0 ( )
This reaction is favoured by high pressure. However the pressure is not increased beyond bar. As
a student of chemistry how will you ustify this?
Answer:- Since the volume of the gaseous products is less than that of the gaseous reactants,high
pressure should favour the oxidation of sulphurdioxide. But a very high pressure may cause the
corrosion of the vessel in which the oxidation is carried. Therefore a pressure of 2-3 bar is
sufficient for the oxidation.
8. d & f Block Elements
Q.1 A car driver was stopped and asked to breath in an electronic device which contained some
chemical.
(i) Why was the driver stopped and asked to breath in an electronic device?
(ii) Name the instrument used by the policeman and the chemical used in it.
(iii) Mention the value of such test.
Ans.(i) The policeman suspected that the driver was drunken. Therefore, he wanted to test the
alcohol content in the blood.
(ii) The instrument called alcometer and the chemical used in it is potassium dichromate .on
silica gel.
(iii) Such tests are essential to curb crime and accidents.
Q.2 A mixture of K2Cr2O7 crystals and conc. H2SO4 was added in two test tube
containing KI and CH3CHO respectively. It was followed by strong
heating. What changes will be observed. Support your answer with suitable chemical equations.
Write associated values.
Ans. K2Cr2O7 +7H2SO4 + 6KI → 3I2 + 4K2SO4 + Cr2(SO4)3 + 7H2O
K2Cr2O7 +H2SO4 + CH3CHO → CH3COOH + K2SO4 + Cr2(SO4)3 + H2O
Scientific attitude and experimental attitude.
9. COORDINATION COMPOUNDS
Q1.As per the Medical Report, Mohit found to be affected with the dearth of
Hemoglobin in his Blood, Mohit being the student of Chemistry was known to
the fact that there are many complex compounds found in nature with specific
metal atom/ion. Such a few complexes are Chlorophyll, Blood pigment, Vitamin
B12 etc. Will this knowledge help, any way, to recover from the dearth of
Hemoglobin to Mohit, what sort of value you find associated with, in this
particular instance?
Ans. Yes, as hemoglobin is the complex of iron.
Values associated :
(i) Use of knowledge of chemistry in daily life.
(ii) Concern about health.
(iii) awareness
Q2.Anurag has selected a science project to estimate the hardness of water
samples collected from different places. He went to water testing laboratory of
his city. There he came to know bout some specific terms like ‘titration’ and
‘EDTA’. Explain these terms. How far his project may be useful for the local
habitants?
Ans. Titration is mode of determination of the amount of a substance by allowing a definite
volume of its solution to react quantitatively with a solution of another substance of known
concentration.
EDTA: Ethylene diamine tetraacetate. It is used as complexing agent in volumetric estimation of
metal ions (Ca+2, Mg2+ and Zn2+).By knowing the percentage of Ca+2, Mg2+ in the water one can
remove these ions from water and can make that water fit for drinking.
Chapter : 10 (HALOALKANES AND HALOARENES)
Q1.Antiseptic is antimicrobial applied on living tissues. Tincture of iodine is a common example.
Rewati had read that iodoform also possesses an appreciable antiseptic property. How will you
explain this? Identify the value associated with it.
Ans: Iodoform is used as an antiseptic, particularly for dressing wounds. Actually, on coming in
contact with skin it decomposes and slowly loses iodine which accounts for the antiseptic
properties of iodoform. Scientific Knowledge and logical thinking.
Q2. Ravi Prasad a farmer has 25 acres of land. He noticed some infection on the leaves of his
crops. He called his friend Raghav, who advised him to use DDT. However, Ravi Prasad
preferred to use dry powder of neem leaves as an insecticide.
A) Mention reasons why Ravi Prasad prefer using neem powder?
B) In your opinion, who took right decision?
C) Write values associated with above decision?
Ans: a) because neem powder will not harm soil.
b) Ravi Prasad.
c) Application of scientific knowledge. Environmental concern.
Q3. Gita regularly cleans her artist father’s metal table with an organic liquid given by her father
due to this regular activity she had eye irritation. After few months she eventually losses vision
in one of her eye.
a) What is the effect of chlorination in the presence of sunlight on methane?
b) Why did gita lose her eye sight?
c) List values associated with the above problem.
Ans: a) Methane gets converted to CCl4
b) Because of release of chorine vapors in the atmosphere.
c) Appropriate knowledge of organic chemical is essential while handling them.
Q4. A farmer cultivating his land near the village pond was also drawing water from it for
irrigation. He used insecticide excessively to protect his crops and improve the harvest, over a
period of time his agricultural growth improved vastly. But the pond lost its aquatic life.
a) Give the IUPAC name of the compound used as an insecticide but not a pesticide.
b) Contrast the activity in plants and aquatic life with insecticides.
c) What value got expressed in student’s suggestions?
Ans: a) 2, 2-Bis(4-Chlorophenyl)-1,1,1-trichloroethane
b) Plant growth improved because it is a very effective insecticide but aquatic life got
destroyed as it is highly toxic to fish.
c) Prompt application of chemistry knowledge, environmental concern.
Q5. A sweet smelling organic compound ‘A’ is slowly oxidized by air in the presence of light to
a highly to a poisonous gas. On warming with silver powder, it carbide on water.Gas’B’ is also
used to make metallic objects reusable. Identify A and B. Write the values associated to use the
reagent as minimum possible to conduct this chemical reaction.
Ans: Compound A is chloroform, Compound B is ethylene. Chloroform is highly toxic in nature
its vapor when inhaled damage the central nervous system. Therefore, it should be handled very
carefully.
Q.6. A manufacturer dealing in A.C plant was using Freon-12 in his AC plant. His friend Raju, who also
deals in similar business, was using liquid ammonia in place of Freon-12.
(i) In your opinion, Who is using right compound in refrigeration plants.
(ii) Mention values associated with above opinion.
Ans: (i) Raju (ii) environmental conservation, knowledge of science, concern to environment.
Chapter : 11
Alcohols, Phenol and Ethers
1. A teacher ordered ethanol for laboratory. She preferred denatured alcohol over absolute
alcohol.a) Give reason for the decision taken by the teacher. (1)
b) What value was kept in mind while taking the decision? (1)
Ans : Value Points:-
 Maintaining discipline
 Concern for environment
 Responsible behaviour
 Social obligation.
2. Duty free ethyl alcohol is supplied to laboratory. This alcohol is mixed with some chemical to
make it unfit for drinking. This alcohol is poisonous and should not be used for drinking.
a) Name the compound witch are mixed with ethyl alcohol to make it unfit for drinking.
b) What purpose are served by those chemicals
c) what is denatured spirit
d) write the value associated with the example
ans:
a)poisonous chemicals are : (i) methanol(ii) pyridine (iii) copper sulphate
b) Pyridine is a foul smelling substance. Copper sulphate makes alcohol blue appearance.
c) Denatured spirit is another name of denatured alcohol.
d) One should not be dishonest and should not do anything which is harmful for the self
and society.
Chapter : 12 ALDEHYDES, KETONES AND CARBOXYLIC ACIDS
Q1. . A boy argues with his sister not to use nail polish and nail polish remover as frequently as it
is
poisonous. His sister rubbishes his arguments stating that all women polishing their nails to
beautify.
Answer the following questions:
(i) Is the brother of the girl justified in his arguments?
(ii) As a student of chemistry what do you think could be reason for such a suggestion?
(iii) Suggest two activities to promote these values.
Ans. . (i) The brother of the girl is justified in his arguments because Nail polish contains two
most common chemicals i.e., formaldehyde and toluene. Both are toxic substances and are
carcinogenic compounds (cancer producing compounds).
(ii) (a) The frequent use may expose to cancer risk.
(b) Breathing in toluene irritate eyes, throat and lungs.
(iii) Spreading awareness about the risk of cancer.
Q2. Drugs Containing Carboxylic Acid. Organic acids characterized by the presence of at least
one carboxyl group. The general formula of a carboxylic acid is R—COOH. The carboxylic
acids find a use in the manufacture of many useful drugs. One such important drug is aspirin.
Answer the following questions:
(i) What is the IUPAC name of the drug? Name the functional groups present in the drug.
(ii) Can the drug be prepared in the lab?
(iii) A person goes to the shopkeeper to get aspirin pills without doctor’s prescription. The
chemist is reluctant to give him pills without doctor’s prescription.
(iv) Which values are reflected in chemists approach?
Ans. (i) Aspirin is acetyl salicyclicacid,O—C—CH3OCOOH
. IUPAC name: 2-Acetoxybenzoic acid or 2-Acetoxy benzene carboxylic acid.
(ii) It can be prepared in lab, by the reaction of salicyclic acid with acetic anhydride.
(iii) No medicines should be given without prescription as an overdose of these pills may result
in death of a person.
(iv) Value: Professional commitment.
Q3.Rancidification of Oils. When oils and even the oily eatables are not used over a time period
these are known to change its odor and its taste i.e., unpleasant and noxious odors and flavors are
given by such samples.
Answer the following questions:
(i) Why the oils and oily eatables develop unpleasant and noxious odors and flavors?
(ii) As a student of chemistry what do you think could be reason and the term you would use to
explain it?
(iii) What you shall do to such eatables i.e., you will dispose it off or give it to your aid?
(iv) Which values are promoted through your actions?
Ans. . (i) The unpleasant odour and flavor results because the fatty acids formed due to
decomposition of fats, oil on hydrolysis or oxidation then undergo further auto oxidation to
generate highly reactive molecules in rancid oils and hence produce unpleasant odour and flavor.
(ii) This is due to oxidation of fats and oils which is called rancidity.
(iii) Such eatables should be disposed off because due to rancidity nutrients as well as the
vitamins in the food are destroy due to highly reactive molecules in rancid oil.
(iv) Value: Nutritional significance.
Q4. A group of students were given to study the properties of aldehydes and ketones in the lab.
They recorded a few observation of their physical properties.
PROPERTY
ALDEHYDE
KETONE
SOLUBILTY
HIGH
LOW
VOLATALITY
MODERATE
HIGH
REACTIVITY
HIGH
LOW
a) Why are aldehydes more reactive and more soluble than ketones?
b) What values can be learnt from behavior of aldehydes?
Ans. a) Aldehydes are more reactive than ketones because they contain only one alkyl group due
to which nucleophilic addition takes place readily whereas inketones due to two bulky alkyl
groups (Steric Hinderance) nucleophilic addition is difficult .
Aldehydes are more soluble than ketones because they form intermolecular H-bonds easily with
water.
b) This shows that aldehydes are more polar than ketones . They are volatile liquids so should be
used very carefully.
Chapter : 13 AMINES
1.
Due to high electron density in the benzene ring aromatic amines are susceptible to aerial oxidation .This
oxidation produces coloured substance called quinines. The presence of one or more electron- donating
groups such as –NH2, -OCH3, -OCH2CH3, etc. in the aromatic amine further increases their reactivity towards
oxidation. To protect these amines from aerial oxidation, they are often stored in form of their salts such as
hydrochlorides, sulphates, etc. This oxidation which is a disadvantage here is often useful in hair dyes which
use aromatic primary amines as colouring material.
Now answer the following questions:
(i)What is the oxidation product of aniline?
(ii) Name a few amines which are stored as their salts.
(iii)Name a few aromatic amines which are used in hair dyes.
(iv) What health problem is associated with the use of these dyes and how can it be checked?
ANS: - (i) Oxidation of aniline gives p-benzoquinone which is yellow in colour
[O]
— NH2
O=
=O
Aniline
p- Benzenoquinone
(ii) Amines which are stored in form of their salts are
C6H5NH2.HCl
Aniline hydrochloride
(C6H5NH2)2H2SO4
Aniline sulphate
(iii) Aromatic amines used in hair dyes are:
H2N
H2N —
— NH2
p- Phenylenediamine
Phenylenediamine
C6H5NHNH2.HCl
Phenylhdrazine hydrochloride
H2N
— NH2
OCH3
p-Methoxy-m-Phenylenediamine
— NH2
OCH2CH3
p-ethoxy-m-
(iv) These amines are suscepted to be carcinogens. Therefore, natural dye, Henna is used as a hair dye.
However, the active constituent of henna is not an aromatic amine but is a quinine actually 2-hydroxy-1, 4naphthoquinone
O
‖
OH
‖
O
2-Hydroxy-1,4-naphthoquinone
2.
Both aliphatic and aromatic amines have diversified uses. The deficiency of some amines causes diseases.
Some amines are used as medicine while some others are poisons. The quaternary salts of some amines are
useful as surfactants/ detergents.
Now answer the following question:(i)Name an amine whose deficiency in the body produces Parkinson’s disease.
(ii)Name a few amines which have been used as medicine.
(iii)Name an amine which was used to kill the great philosopher, Socrates.
(iv)Name a quaternary salt which is used as a detergent.
ANS: - (i) The deficiency of the amine called dopamine causes Parkinson’s disease.
HO
HO — — CH2CH2NH2
Dopamine
(ii) Neo-synephrine is used in nose sprays to reduce swelling in nasal membranes
HO
OH
│
— CH—CH2—NH— CH3
Neo- synephrine
Benzocaine is used as a local anaesthetic agent.
H2N—
— COOC2H3
Benzocaine
Atropine, an alkaloid, is used as an anaesthetic which dilates the pupil of eye for examination. The alkaloid
quinine is used for treatment of malaria.
(iii) The alkaloid conine, extracted from the bark of hemlock plant is extremely toxic. It was used to kill
Socrates, the great philosopher of Athens
(iv)The quaternary salt, cetyltrimethylammonium chloride is a detergent
CH3 —(CH2)15 —N(CH3)3Cl¯
Cetyltrimethylammonium chloride
Being expensive, these detergents are quite extensively used as germicides rather than cleansing agents.
3.
Aromatic amines react with nitrous acid at 273-278 K to produce diazonium salts which are widely used for
preparation of a variety of aromatic compounds via substitution. They also couple with phenols/amines to
form azo dyes which are used either as indicators or as dyes for fabrics.
Now answer the following question:(i)What are azo dyes?
(ii)What is a coupling reaction?
(iii)Write chemical equations for the azo dye produced when benzenediazonium chloride reacts with
phenol and N, N-dimethylaniline.
ANS: - (i) Dyes containing –N=N- bonds are called azo dyes.
(ii) The reaction of diazonium salts with phenols and amines to produce compounds of the type
Ar―N = N―Ar is called coupling reaction.
(iii) COUPLING REACTION: When Benzene diazonium Chloride is treated with phenol or aniline
corresponding azo compounds are formed.
N2+Cl- + H
OH
N=N
OH
Chapter : 14 (BIOMOLECULES)
Q. 1 Meena’s son who is 2 years old started walking that time she observed that he has bow legs
parents consulted a doctor and has suggested some remedy
a) What is the remedy suggested by the doctor?
b) Name the sources in which the mentioned vitamin is present ?
c) What value you have gained from this?
Ans:- a)The doctor informed that it was due to the deficiency of vitamin D.He suggested to
include food containing more vitamin D in the diet.
b) Cod liver oil, butter, milk, eggs, liver and meat.
c) Vitamins play an important role in our day to day life. Inorder to be healthy we must take
vitamins along with carbohydrates, proteins and fat.
Q.2 Humans, monkeys and guinea pigs do not have the enzymes necessary for the synthesis of
vitamin C, so they must include the vitamin in their diets. It is also required for the synthesis of
collagen, which is the structural protein of skin tendors, connective tissue and bone.
(i) Write structure of vitamin C and the functional groups therein.
(ii) Is it acetic in nature?? What is the common name of vitamin C?
(iii) What is the oxidation product of vitamin C?
Answers)
(i)
(ii) It is acidic due to enolic-OH.
Common name is ascorbic acid.
(iii)
Chapter : 15 Polymer
1. Reetu wanted to buy milk cup for her son of 3-4 years of age; but was unable to decide
between cup made of porcelain and melamine, since both looked colourful and decorative on the
rack. She sought the opinion of her younger brother, a student of XII standard.
a) Which cup would the young man select, and why?
b) What are the values associated with his selection of the specific material?
2. Rajesh went to textile shop with his mother to purchase dress material for his school uniform.
Rajesh wanted pure cotton fabric which looked bright, while mother insisted on blended fabric
with 67% terylene. a) In your opinion, who is right?
b) What are the monomers of Terylene?
c) What are the values involved in the selection of the fabric?
3. Two iron plates, with dents were allotted to two students for plating and study of prevention of
rusting. The first student selected tin for coating his plate, while the second chose zinc for the
same purpose.
a) Who do you think made the right choice, and why?
b) Mention one value associated with the study of corrosion.
4. Ram’s mother always followed very traditional way of cooking using earthen wares, copper
utensil. Her daughter replaced all the kitchen utensils with Teflon coated ones.
a) In your opinion who is correct in the present life situation?
b) What is the monomer of Teflon? What is its structure?
c) What are the values involved?
5. The Government order directs the shop keepers to charge their customers bags, to take the
items that they purchase. \ a) Name the different types of polythene available.
b) Why does the Government impose such an order?
c) What are the values involved in the Government order?
Chapter : 16 Chemistry in everyday life
Q. 1. a) Rahul’s father recovered from a massive heart attack. As follow up doctor gave him
Aspirin.Why?
b) After some time he started to develop some stomach ache.Then his wife gave him some
butter milkWhy?
c)What value do you get from this?
Ans:
a)Aspirin is a blood thinner. Hence for a patient suffering from heart attack is given
Aspirin. Aspirin is acetylated salicylic acid. In the presence of acid in the stomach it
undergoes hydrolysis to form two acids salicylic acid and acetic acid. This increases the
acidity in the Stomach.
(1)
b)To neutralize this acidity butter milk is also given.
(1)
c)Being dedicated and faithful.
Q.2. Ashraf is 50 years old and has diabetes. He uses saccharine as sweetening agent in tea
and coffee and sugar free in sweets. Lakshmi too is diabetic. She controls her sugar level
in diet by using less sugar and by exercising.
a. Wh o is able to handle diabetes more efficiently and why?
(1)
b. What value do you derive from this?
(1)
c. What are the harmful effects of artificial sweeteners?
(1)
Ans: a. Lakshmi is able to handle diabetes better, because exercises activate the pancreases
to produce insulin. Exercise keeps one fit and fine.
b. It is necessary to lead a disciplined life.
c. Researchers have shown that the artificial sweeteners have harmful effect on the body
because they are not excreted easily.
Q.3. Almelu did not like the costlier brand of dish washer because she was not satisfied by using
less quantity of the dishwasher, so she bought the cheaper brand of dishwasher and used large
amounts of it.
a. As a student of chemistry what would you advise Almelu to use?
(1)
b. Why? Explain.
(1)
c. What value did you impart to Almelu?
Ans: a. I would advise Almelu to use smaller quantities of the costlier detergent.
b. Almelo was pouring detergents into the drain. These detergents are not biodegradable.
Branched detergents are highly non- degradable because the microbes cannot attack it. Straight
chain detergents are being prepared these days to reduce the pollution problem. The costlier
detergent contains straight chain hydrocarbon.
c. The value imparted was to use environmentally friendly substances.
Q.4. Pradeep had very high fever. He was given strong antibiotics. But after recovering
from fever he was not able to digest food and was feeling too weak. The grandmother who
lived in his neighborhood suggested him to take lots of fruits and vegetables.
a.Why?
(1)
b.What is the remedy for this?
(1)
c.What was the value that Pradeep had by taking fruits and vegetables?
(1)
Ans:
a. Rise in temperature denatures the proteins in our body. The enzymes which are also proteins
get denatured. The body has to regenerate these enzymes. Till then Pradeep will continue to
feel weak as the enzymes to digest food and for respiration are destroyed due to high
temperature and change in pH. Even after the enzymes are regenerated ,vitamins which act as
prosthetic groups in enzyme action are to be taken from an external source.
b. By taking fruits and vegetables Pradeep is actually taking in vitamins.
c. He obeyed an elderly person’s advice.
Prepared By – Smt. Seema Sharma (PGT Chem.) KV AFS JAISALMER
___________________________________________________________________________