1st Year Lahore Board 2013
Chemistry – Paper I
Time Allowed: 20 Minutes
(Objective Type)
Group – II
Max. Marks: 17
NOTE: Four answers are given against each question in columns A, B, C and D. Select the right
answer and on the separate Answer Sheet, fill the circle A, B, C or D with pen or marker in
front of that question number.
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
11.
12.
13.
14.
15.
Acetone and chloroform are soluble in each other due to:
(A) Intermolecular
(B) Ionic-dipole interaction
(C) Instantaneous dipole
(D) All of these
–10
The solubility product of AgCl is 2.0 × 10 mole 2 dm3. The maximum concentration of Ag+ ions in
the solution is:
(A) 2.0 × 10–10 mole dm–3
(B) 1.4 × 10–5 mole dm–3
(C) 1.0 × 10–10 mole dm–3
(D) 4.0 × 10–20 mole dm–3
The existence of a compound in more than one crystalline forms is called:
(A) Anisotropy
(B) Isomorphism
(C) Allotropy
(D) Polymorphism
For the reaction NaOH + HCl  NaCl + H2O , the change in enthalpy is called:
(A) Heat of reaction
(B) Heat of formation
(C) Heat of neutralization
(D) Heat of combustion
How many isotopes are present in palladium:
(A) Four
(B) Five
(C) Six
(D) Seven
The gaseous of ethane is:
(A) Trigonal planar
(B) Linear
(C) V-shaped
(D) Tetrahedral
The unit of the rate constant is the same as that of the rate of reaction in:
(A) First order reaction
(B) Second order reaction
(C) Third order reaction
(D) Zero order reaction
A solution of glucose is 10% w/v. The volume in which 1 gram mole of it is dissolved will be:
(A) 1 dm3
(B) 1.8 dm3
(C) 200 cm3
(D) 900 cm3
The oxidation number of chromium in K2Cr2O7 is:
(A) 14
(B) 12
(C) 6
(D) 13
27g of Al will react completely with how much mass of O2, to produce Al2 O3:
(A) 8 g of oxygen
(B) 16 g of oxygen
(C) 32 g of oxygen
(D) 24 g of oxygen
The velocity of photon is:
(A) Independent of the wavelength
(B) Depends on its wavelength
(C) Equal to square of its amplitude
(D) Depends on its source
Stronger the oxidizing agent, greater is the:
(A) Oxidation potential
(B) Reduction potential
(C) Redox positional
(D) E.M.F. of cell
Which of the hydrogen halides has the highest percentage of ionic character?
(A) HF
(B) HBr
(C) HCl
(D) HI
The term pH was introduced by:
(A) Henderson
(B) Sorenson
(C) Goldstein
(D) Thomson
Pressure remaining constant at which temperature of the volume of a gas will become twice of
what it is at 0oC.
(A) 546oC
(B) 200oC
(C) 546 K
(D) 273 K
e
value for the positive rays is maximum for:
m
16.
The
17.
(A) Hydrogen
(B) Helium
(C) Oxygen
I2 dissolves in water in the presence of KI due to the formation of:
(A) I2
(B) I 
(C) I3
(D) Nitrogen
(D) I4
1st Year Lahore Board 2013
Chemistry – Paper I
Time Allowed: 3. 10 Hours
(Essay Type)
Group – II
Max. Marks: 83
PART – I
2.
3.
Write short answers to any EIGHT (8) questions:
16
(i)
Why theoretical yield is great than actual yield?
(ii)
What is mass spectrum?
(iii)
Define empirical formula and molecular formula with example.
(iv)
What is solvent extraction?
(v)
Write down the name of Eight solvent used in crystallization.
(vi)
Calculate the value of R in SI unit.
(vii)
Give four fundamental postulates of kinetic molecular theory of gases.
(viii)
Why the dipole moment of SO 2 is 1.61 D but that of SO3 is zero?
(ix)
Why one feels sense of cooling under the fan after bath?
(x)
Write down two applications of liquid crystals.
(xi)
Define isomorphism and polymorphism with example.
(xii)
Why ionic crystals are highly brittle?
Write short answers to any EIGHT (8) questions:
16
(i)
Give reason for the production of positive rays.
(ii)
Calculate mass of an electron from its
(iii)
How the K-series, L-series and M-series of x-rays spectrum are produced?
(iv)
State Heisenberg’s Uncertainty principle and give its mathematical expression.
(v)
Why the ionic radius of Cl – ion increases from 99 pm to 181 pm?
(vi)
How a coordinate covalent bond differs from covalent bond?
(vii)
Why the energy of antibonding molecular orbital is higher than corresponding bonding
e
value.
m
molecular orbitals?
(viii)
Why the energy of antibonding molecular orbital is higher than corresponding bonding
molecular orbitals?
4.
(ix)
State the Hess’s law of constant heat summation.
(x)
Define enthalpy of atomization and give an example.
(xi)
Write two applications of equilibrium constant.
(xii)
Write two uses of buffer solution.
Write short answers to any SIX (6) questions:
12
(i)
Define pH and pOH.
(ii)
Why Beckmann’s thermometer is used to measure the depression in freezing point?
(iii)
Differentiate between ideal and non-ideal solutions.
(iv)
One molal solution of glucose is dilute as compared to one molar solution of glucose. Justify
it.
(v)
Write down two functions of salt bridge in a galvanic cell.
(vi)
Write down reactions taking place at the electrodes on the discharging of Nickle -Cadmium
Cell.
(vii)
2
Calculate the oxidation number of Cr and K2CrO4 and Cr2O 7 .
(viii)
Define and give an example of the process of activation of a crystal.
(ix)
What happen to the rate of a chemical reaction with the passage of time?
PART – II
NOTE: Attempt any THREE questions.
5.
(a)
(b)
What are ionic solids? Give their properties in detail.
4
Calculate the number of grams of Al2S3 which can be prepared by the reaction of 20g of Al
and 30g of sulphur. How much the non-limiting reactant is in excess?
4
(Atomic masses:
Al:27 S:32)
6.
(a)
(b)
Define electron affinity. Name the factors affecting it. How does it very in the periodic
table?
4
Define enthalpy of reaction. How is it measured by glass calorimeter?
4
7.
(a)
(b)
Describe Lind’s method for the Liquefaction of gases.
Write Millikan’s Oil Drop Method for the measurement of charge of an electron.
8.
(a)
Describe the electrolysis of molten sodium chloride and a concentrated solution of sodium
chloride.
4
N2 (g) , and H2 (g) combine to give NH3 (g). The value of KC in this reaction is 6.0 × 10–2 .
Calculate the value of KP for this reaction.
4
(b)
9.
(a)
(b)
4
4
State and explain Raoult’s law in three forms.
4
Explain Arrhenius equations. How does it help us to calculate the energy of activation of a
reaction?
4
PART – III
NOTE: Attempt any TWO questions.
(i)
(ii)
Write down standard solution, chemical equation with mole ratio, indicator with end point,
procedure and supposed readings with calculations for Part A, b and C.
1, 1, 1, 1, 1
Write down material requiem, diagram and procedure for Part D and E.
1, 1, 3
A.
4 g of a mixture of Na2CO3 are dissolve din 500 cm3 solution. Find out the % age composition of the
mixture. (Molecular mass of Na2CO3 = 106)
5
B.
3 g of partially oxidized ferrous sulphate are dissolved in 100cm 3 solution. Find out % age
oxidation. (Molecular Mass of FeSO4 = 152)
5
C.
20 g of Na2 S2O3 are dissolved in one dm3 solution. Find out the % age of sulphur. (Molecular mass
of Na2 S2O3 =158)
5
D.
Identify Cu2+ and Cd2+ ions by paper chromatography.
5
E.
Purify commercial sodium chloride by common ion effect.
5