Unit – 5 p-block Element
Semester II
Section – A
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Which one of the following is decreasing in period from left to right ?
(a) electro negativity
(b) ionization enthalpy
(c) oxidizing capacity
(d) atomic radius
(d)
Which one of the following is decreasing in group from top to bottom ?
(a) atomic radius
(b) oxidizing power
(c) metallic character
(d) van der waals radius
(b)
Which state is most stable in Ga ?
(a) +3
(b) +2
(c) +1
(d) +4
(c)
Which element is available in Turkey ?
(a) B
(b) Si
(c) P
(d) S
(a)
Arrange the following in ascending order of abundance in earth crust ?
(a) Al > Si > O
(b) O > Al > Si
(c) Al < Si < O
(d) O < Si < Al
(c)
In which state of India, Al is available ?
(a) Gujarat
(b) Madhya Pradesh
(c) Rajasthan
(d) Tamilnadu
(b)
Which one of the following element is available from Germanite ?
(a) B
(b) Ga
(c) P
(d) Tl
(b)
Give difference between IE1 Ga and IE1 Al.
(a) 1 KJ
(b) 577 KJ
(c) 578 KJ
(d) 100 KJ
(a)
Which one of the following is non-metal ?
(a) Ba
(b) Al
(c) Ga
(d) Tl
(d)
Give the order of boiling point of group 13 elements.
(a) B > Al > Ga > In > Tl
(b) B > Al > Ga < In < Tl
(c) B < Al < Ga < In < T
(d) B > Al < Ga < In < Tl
(b)
Which one of the following does not show maximum inert pair effect ?
(a) Al
(b) Ga
(c) In
(d) Tl
(a)
Which one of the following reaction is in favour of +1 oxidation state ?
Dr. Vikram Panchal/11th Science / Chemistry(52-E)
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(a) Tl+3(aq) + 2e-  Tl+(aq)
E = – 1.25 V
+3
+
(b) Tl (aq) + 2e  Tl (aq)
E = – 2.25 V
+3
+
(c) Tl (aq) + 2e  Tl (aq)
E = 3.25 V
+3
+
(d) Tl (aq)  Tl (aq) + 2e
E = – 1.25 V
(d)
IUPAC name of LiAlH4 would be
(a) Lithium aluminium hydride
(b) Lithium tetrahydro aluminate (III)
(c) Lithium tetrahydroxy aluminate (III)
(d) Lithium tetrahydro aluminate
(b)
State the use of LiAlH4
(a) as a catalyst
(b) as an oxidizing agent in organic reaction
(c) as a reducing agent in organic reaction (d) for addition of metal in organic reaction
(c)
The molecular formula of Borane is
(a) Bn Hn+6
(b) Bn Hn+4
(c) Bn H2n+2
(d) (a) and (b)
(d)
Which one of the following compound behave like Lewis acid ?
(a) In H3
(b) BI3
(c) AlCl3
(d) all
(d)
Give order of acidic strength of BX3.
(a) BI3 > BBr3 > BCl3 > BF3
(b) BI3 < BBr3 < BCl3 < BF3
(c) BI3 > BBr3 < BCl3 < BF3
(d) BI3 > BF3 > BBr3 > BCl3
(a)
Why do AlCl3 and BF3 used as catalyst ?
(a) because it is available as dimeric
(b) because it is Lewis acid
(c) because it is Lewis base
(d) because it is neutral
(b)
Which one of the following is not octahedral ?
(a) [Al F6 ]3((b) [In Cl6]3(c) [BF4](c)
[Mn (H2O)6]3+ complex is known as
(a) hydride
(b) hydrate
(c) aqua ion
(c)
Give formula of alum.
(a) K2SO4 Al2(SO4)3 24H2O
(b) K2SO4 AlSO4 24H2O
(c) K2SO4 Al2(SO4)3 12H2O
(d) K2SO4 Al2(SO4)3 H2O
(a)
The alum is known as
(a) Potash alum
(b) alumina (c) Potassium sulphate
Dr. Vikram Panchal/11th Science / Chemistry(52-E)
(d) [Al (H2O)6]3+
(d) all
(d) Mhor salt
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(a)
Which one of the following is non-metal ?
(a) Ga
(b) Al
(c) B
(d) In
(c)
Which one of the following is not reacting with water ?
(a) Na
(b) B
(c) Al
(d) Mg
(b)
10
B and 11B are in proportion
(a) 40 % , 60 %
(b) 80 % , 20 %
(c) 50 % , 50 %
(d) 20 % , 80 %
(d)
Boron reacts with _______ at high temperature.
(a) strong reducing agent
(b) strong oxidizing agent
(c) metal
(d) none
(b)
Boron does not react with …………
(a) HCl
(b) HNO3
(c) H2SO4
(d) All
(a)
Boron reacts with alkali to release ………. gas.
(a) SO2
(b) NO2
(c) H2
(d) none
(c)
Boron reacts with H2SO4 to release ……….. gas.
(a) SO3
(b) SO
(c) S2O3
(d) none
(d)
Which one of the following compound have oxidation state of Boron -3 ?
(a) BN
(b) BX3
(c) CrB
(d) K3BO3
(c)
Which metal does not react with Boron ?
(a) Ca
(b) K
(c) V
(d) Fe
(b)
The name of Borax is
(a) sodium borate
(b) sodium meta borate
(c) sodium ortho borate
(d) sodium tetra borate
(d)
Complete the following reaction.

4H3BO3
+
Na2CO3
 A + B + C
(a) A = Na2B4O7
B = 6H2O
C = CO2
(b) A = Na2B4O7
B = H2O
C = CO2
(c) A = Na2B4O7
B = 6H2O2
C = CO
(d) A = Na2B4O7
B = 6H2O2
C = CO
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(a)
Which form of Borax is octahedral ?
(a) Na2B4O7 10H2O
(b) Na2B4O7 5H2O
(c) Na2B4O7
(d) NaBO2
(b)
The aqueous solution of borax is
(a) acidic
(b) basic
(c) neutral
(d) insoluble
(b)
The chemical composition of borax bead is
(a) B2O3 + NaBO2
(b) B2O3 + 2NaBO2 (c) BO + NaBO2
(d) 2B2O3 + NaBO2
(b)
The colour of borax bead for testing Ni+2 ion would be
(a) brown
(b) blue
(c) pink
(d) green
(a)
The colour of borax bead for testing Co2+ would be
(a) brown
(b) green
(c) blue
(d) pink
(c)
The colour of borax bead for testing Cu2+ would be
(a) blue
(b) brown
(c) green
(d) pink
(a)
The colour of borax bead for testing Mn2+ would be
(a) blue
(b) green
(c) brown
(d) pink
(d)
Which one of the following is incorrect ?
(a) Borax is used in preparation of optical glass
(b) Borax is used to make soft water from hard water
(c) Borax is used in making pigments
(d) Borax is used in making candle
(c)

Ca2B6O11
+ 11H2O + 4SO2  A + B
(a) A = H3BO3
B = Ca(HSO3)2
(b) A = 6H3BO3
B = 2Ca(HSO3)2
(c) A = 3H3BO3
B = 2Ca(HSO3)2
(d) A = 6H3BO3
B = Ca(HSO3)2
(b)
The formula of tetra boric acid is
(a) H3BO3
(b) HBO2
(c) H2B4O7
(d) none
(c)
Basicity of boric acid is
Dr. Vikram Panchal/11th Science / Chemistry(52-E)
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(a) 1
(b) 2
(c) 3
(d) 4
(a)
Which one of the following reaction proves acidic nature of boric acid ?
(a) H3BO3(aq)  3H+(aq) +
BO33-(aq)
(b) H3BO3(aq)  H+(aq) +
H2BO31-(aq)
(c) H3BO3 + 2H2O  3HBO32-(aq) +
2H3O+(aq)
(d) H3BO3 + H2O  {B(OH)4}-1 +
H+(aq)
(d)
The formula of ethyl borate is
(a) B(OC2H5)2
(b) B(OC2H5)3
(c) B(OC2H5)
(d) B(OC2H4)
(b)
Which reaction is used for preparation of diborane ?
(a) Reaction between iodine and sodium boron hydride in presence of polyether solvent.
(b) Heating BF3 with LiH at 450 K.
(c) Heating BCl3 with LiH at 450 K.
(d) all
(d)
The structure of Borazene is
(a) B3N3H5
(b) B3N3H6
(c) B3NH3
(d) BN3H6
(b)
Borazene is prepared by
(a) Heating diborane with NH3 at 450 K
(b) Hydrolysis of diborane
(c) oxidation of diborane
(d) reaction of diborane with HNO3
(a)
Hydrolysis of diborane gives
(a) Boron hydride
(b) Borazene
(c) Boric acid
(d) Boron oxide
(c)
What is the characteristic of structure of diborane ?
(a) All hydrogens are planar.
(b) All hydrogens are in different planes.
(c) Four end hydrogens are in one plane and out of two bridge hydrogens, one is above
and another is below
(d) Out of four end hydrogens, two are below and two above and two bridge hydrogens
are in one plane.
(c)
The formula of sodium aluminate is
(a) Na [Al(OH)4]
(b) Na2[Al(OH)4]
(c) Na3AlO2
(d) Na3AlO3
(a)
Which one of the following is dimeric ?
(a) NaCl
(b) AlCl3
(c) KCl
(d) LiCl
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(b)
Which one of the following is universal reducing agent in organic reaction ?
(a) LiAlH4
(b) FeCl3
(c) AlCl3
(d) LiCl
(a)
Which one of the following is used in Hall-Heroult process ?
(a) cryolite
(b) feldspar
(c) Beryl
(d) Olivine
(a)
Which one of the following is not a mineral of Al ?
(a) cryolite
(b) feldspar
(c) Beryl
(d) Olivine
(d)
Which one of the following statements is incorrect ?
(a) Al is light metal
(b) Al is good conductor of heat and electricity.
(c) There is a passive layer of Al2O3 on the surface of Al.
(d) Al dissolves in dil. HCl but not in NaOH.
(d)
The common formula of alum is
(a) M Al2 (SO4)3 12H2O
(b) M2 Al (SO4) 2 12H2O
(c) M Al (SO4)3 12H2O
(d) M Al (SO4) 2 12H2O
(d)
When AlCl3 dissolves in water it gives
(a) Al+3(aq)
+
2Cl-(aq)
(b) Al2O3
+
6HCl
(c) [Al(OH)6]-3
+
3HCl
(d) [Al(H2O)6]+3
+
3Cl(d)
Which one of the following is not a binary inorganic compound ?
(a) calcium carbide (b) silicon carbide
(c) methane (d) HCN
(c)
The electronic configuration of Tin.
(a) [Ar] 3d10 4s2 4p2
(b) [Kr] 4d10 5s2 5p2
(c) [Kr] 4f14 5d10 6s2 6p2
(d) none
(b)
Carbon is the _______ most abundant element by weight out of elements obtained from
the earth’s crust.
(a) first
(b) second
(c) fifteenth (d) seventeenth
(d)
Carbon with metal is in the form of
(a) carbonate
(b) cyanide
(c) CO2
(d) CO
(a)
The % of Si in earth’s crust would be
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(a) 25.7 %
(b) 27.7 %
(c) 20.7 %
(d) 28.7 %
(b)
Give order of ionization enthalpy of group 14.
(a) C > Si > Ge > Sn < Pb
(b) C > Si > Ge > Sn > Pb
(c) C > Si > Ge < Sn > Pb
(d) C < Si < Ge < Sn < Pb
(a)
The no. of crystalline allotropes of carbon are
(a) 1
(b) 2
(c) 3
(d) 4
(c)
Which one of the following elements of group 14 does not have co-ordination no. greater
than 4 ?
(a) C
(b) Si
(c) Ge
(d) Sn
(a)
Which one of the following elements have the most stable state +2 ?
(a) C
(b) Si
(c) Sn
(d) Pb
(d)
Which is the shape of SiCl4 ?
(a) square planar
(b) tetrahedral
(c) octahedral
(d) none
(b)
The hydrolysis of SiCl4 gives
(a) Si(OH)4 and HCl
(b) SiO2 and HCl
(c) Si(OH)2 and HCl
(d) SiO4-4 + H2O
(a)
The hydrolysis of SnCl4 gives
(a) Sn(OH)4
(b) SnO2
(c) Sn(OH)2
(d) SnO
(b)
Which one of the following is yellow ?
(a) PbCl2
(b) PbBr2
(c) PbI2
(d) PbCl4
(C)
The shape of SiO2 would be
(a) linear
(b) tetrahedral
(c) trigonal planar
(d) octahedral
(b)
The use of quartz is
(a) as a piezo electric crystal
(b) as a lattice oscillator
(c) as a transducer
(d) all
(d)
Which one of the following possess basic character ?
(a) SiO2
(b) GeO2
(c) SnO2
(d) PbO2
(d)
Dr. Vikram Panchal/11th Science / Chemistry(52-E)
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On heating tin oxalate, we get
(a) stannous oxide, CO2
(b) stannous oxide, CO
(c) stannous oxide, CO, CO2
(d) stannic oxide, CO, CO2
(c)
Which one of the following is correct ?
(a) The bonding capacity of carbon is four and other elements of the group has more than
four
(b) The C-C bond enthalpy is not 348 KJ/mole.
(c) Carbon can not form p - p bond
(d) all
(a)
Who discovered Fullerene ?
(a) H.W Kroto, R.E Smalley and R.F Curl (b) H.W Kroto, R.E Curl and B.F Curl
(c) R. Kroto, H. Smalley and R. Curl
(d) none
(a)
The hybridization of carbon in diamond is
(a) sp
(b) sp2
(c) sp3
(d) none
(c)
The hybridization of carbon in graphite is
(a) sp
(b) sp2
(c) sp3
(d) none
(b)
The molecular formula of fullerene is
(a) C60
(b) C70
(c) C80
(d) (a) and (b)
(d)
The name of C60 is
(a) Fullerene
(b) Buck minister
(c) soccer ball
(d) all
(d)
The structure of Bucky Ball is
(a) It contains ten rinds with 5 carbon and twenty rings with 6 carbons.
(b) It contains twelve rings with 5 carbons and twenty rings with 6 carbon.
(c) It contains twelve rings with 5 carbons and ten rings with 6 carbon.
(d) none
(b)
The hybridization of carbon in fullerene is
(a) sp
(b) sp2
(c) sp3
(d) none
(b)
C60 dissolves in toluene give ________ colour.
(a) violet
(b) orange
(c) red
(d) yellow
(a)
C70 dissolves in toluene give ________ colour.
(a) violet
(b) orange-red (c) red
(d) yellow
Dr. Vikram Panchal/11th Science / Chemistry(52-E)
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(b)
Which one of the following shows reducing nature of carbon ?
electric arc
(a) 2C + H2  C2H2
(b) 2Be + C  Be2C
(c) PbSO4 + 4C  PbS + 4CO
(d) all
(c)
The formula of Beryllium carbide is
(a) BeC
(b) Be2C3
(c) Be2C
(d) BeC2
(c)
The formula of mellitic acid is
(a) C6(COOH)6
(b) C6H6(COOH)6
(c) C6H5(COOH)6
(d) C6(COOH)12
(a)
How does mellitic acid prepared ?
(a) by reaction of C with PbSO4
(b) by reaction of C with HNO3
(c) by reaction of C with H2SO4
(d) by reaction of C with Fe2O3
(C)
Which substance is used as fire extinguisher ?
(a) CF4
(b) CCl4
(c) CBr4
(d) CI4
(b)
Which substance is known as Freon ?
(a) CF4
(b) CF2Cl2
(c) CCl4
(d) CHCl3
(b)
Which substance is used for vulcanizing rubber ?
(a) CO2
(b) CS2
(c) CF2Cl2
(d) CCl4
(b)
The formula of carborandum is
(a) SiO2
(b) CS2
(c) CaC2
(d) SiC
(d)
The dye of coin making is made up of
(a) WC
(b) CaC2
(c) SiC
(d) Be4C
(a)
Which substance is used in making acetylene ?
(a) WC
(b) CaI2
(c) SiC
(d) Be4C
(b)
The uses of acetylene is
(a) welding (b) preparation of ethanol
(c) preparation of acetic acid
(d) all
(d)
How does CO formed in laboratory ?
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(a) by combustion of carbon
(b) by reduction of ZnO with carbon
(c) heating HCOOH and conc. H2SO4 at 373-413 K (d) all
(c)
Which coloured flame appear on combustion of CO ?
(a) red
(b) blue
(c) yellow
(d) violet
(b)
The name of Ni(CO)4 is
(a) nickel tricarbonyl
(b) nickel tetra carbon monoxide
(c) nickel(0) tetracarbonyl
(d) all
(c)
The name of [Fe(CO)5] is
(a) iron penta carbonyl
(b) ferrous penta carbonyl
(c) ferric penta carbonyl
(d) all
(a)
The oxidation no. of Fe in [Fe(CO)5] is
(a) 0
((b) 1
(c) 4
(d) 5
(a)
Which one is used in preparation of magnetic tape ?
(a) CO
(b) [Fe(CO)5]
(c) Ni(CO)4
(d) Fe2O3
(b)
How does CO2 prepared in lab ?
(a) by heating carbon
(b) by heating methane
(c) by adding HCl in CaCO3
(d) by hydrolysis of glucose
(c)
CO2 is ______ times heavier than air.
(a) 1.5
(b) 2
(c) 2.5
(d) 3
(a)
What is meant by dry ice ?
(a) H2O(s)
(b) CO(s)
(c) H2O + H2SO4
(d) CO2(s)
(d)
Which one of the following is combustible in presence of CO2 ?
(a) Fe
(b) Mg
(c) Cr
(d) Ni
(b)
The Basicity of carbonic acid (H2CO3) is
(a) 1
(b) 2
(c) 3
(d) 4
(b)
The temperature in mixture of solid CO2 and ether is upto
(a) 160 K
(b) 165 K
(c) 265 K
(d) 65 K
(b)
The name of method for preparation of Na2CO3 from CO2 is
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(a) Solvay process
(b) Carius process
(c) Down process
(d) Mond-carbonyl process
(a)
The common name of Silane is
(a) Sin H2n+2
(b) Sin H2n
(c) Sin H2n-2
(d) None
(a)
How many types of pure silica are known ?
(a) 22
(b) more than 22
(c) less than 22
(d) 8
(b)
The amorphous form of SiO2 is
(a) quartz
(b) tridymite
(c) kieselgur
(d) crystobalite
(c)
Which type of SiO2 is used in purification of water ?
(a) quartz
(b) tridymite
(c) kieselgur
(d) crystobalite
(c)
Silicic acid is prepared
(a) by hydrolysis of SiO2
(b) by hydrolysis of SiCl4
(c) by melting SiO2 in NaOH
(d) None
(b)
The Basicity of Silicic acid is
(a) 1
(b) 2
(c) 3
(d) 4
(d)
In the first step of preparation of Silisic acid.
(a) one chlorine is removed from SiCl4
(b) one chlorine is removed and OH group attached to SiCl4
(c) water join with Si using d orbitals by forming co-ordinate covalent bond.
(d) all
(c)
In the second step of preparation of Silicic acid
(a) SiCl4 reacts with water
(b) H from H2O and Cl from SiCl4 combine and HCl is released.
(c) four chlorine are removed from SiCl4.
(d) none
(b)
Silicones is _______ compound.
(a) synthetic
(b) natural
(c) semi synthetic
(d) all
(a)
Why does R2SiO known as silicones ?
(a) because of presence of oxygen
(b) because of presence of R
(c) because of similar structure of ketone
(d) all
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145.
Ans
146.
Ans
147.
Ans
148.
Ans
149.
Ans
150.
Ans
151.
Ans
152.
Ans
153.
(c)
How does dimethyl chloro silane prepared ?
(a) reaction between CH3Cl and Si at 670 K
(b) reaction between CH3Cl and Si at 570 K in presence of Cu catalyst.
(c) reaction between CH3Cl and Si at 470 K in presence of Cu catalyst.
(d) reaction between CH3Cl and Si at 570 K in presence of Ni catalyst.
(b)
The formula of dimethyl chloro silane is
(a) CH3 SiCl
(b) (CH3)2 SiCl
(c) (CH3)2 SiCl2
(d) (CH3)2 SiCl4
(c)
The repeating unit of silicones is
(a) (CH3)2 Si
(b) (CH3)2 SiO2
(c) (CH3)2 SiO3
(d) (CH3)2 SiO
(d)
The foam resistance used in cosmetic is
(a) tetra methyl silane
(b) silicones
(c) silica gel
(d) SiCl4
(b)
_______ % of earth crust layer is made up of silicates and Si
(a) 95 %
(b) 85 %
(c) 50 %
(d) 97 %
(a)
The example of ortho silicate is
(a) wallastonite
(b) dioposide
(c) Forestorite
(d) tremolite
(c)
The thortveitite is
(a) ortho silicate
(b) cyclic silicate
(c) pyro silicate
(d) ring silicate
(c)
Which one of the following is chain silicate ?
(a) Beryl
(b) Zircon
(c) Hemimorphte
(d) spodumene
(d)
The formula of tri-molyte is
(a) Ca2 Mg5 (Si8 O22) (OH)2
(b) Ca2 Mg5 (Si4 O11) (OH)2
(c) Ca2 Mg3 (Si8 O22) (OH)2
(d) Ca2 Mg5 (Si8 O22) (OH)
(a)
The formula of Talc is
(a) Mg(Si4O11) (OH)2
(b) Mg3(Si4O10) (OH)2
(c) Mg2(Si4O10) (OH)2
(d) Mg2(Si4O11) (OH)
(b)
Which one of the following is incorrect ?
(a) Si is second element of group 14
(b) SiCl4 can be hydrolysed
Dr. Vikram Panchal/11th Science / Chemistry(52-E)
Page 12
Ans
154
Ans
155.
Ans
156.
Ans
157.
Ans
158.
Ans
159.
Ans
160.
Ans
161.
Ans
162.
Ans
(c) Si = Si or Si  Si is not possible due to larger size of silicon
(d) There is van der waals force of attraction between SiO2 molecules
(d)
Which one of the following is incorrect ?
(a) Si is used as semi conductor
(b) SiC is known as carborandom
(c) Si is available in free stable
(d) Si is present in mica.
(c)
Which of one the following mineral of tin ?
(a) Cerussite
(b) Anglesite
(c) Casetirite
(d) cinnabar
(c)
Which one of the following is incorrect ?
(a) compounds of Sn2+ and Pb2+ are ionic compounds of Sn4+ and Pb4+ are covalent.
(b) SnII is reducing agent.
(c) PbII is more stable than PbIV
(d) Pb(C2H5)2 is added into petrol as antiknocking agent
(d)
Which one of the following has minimum ionic character ?
(a) PbF2
(b) PbCl2
(c) PbBr2
(d) PbI2
(d)
Which one of the following has minimum ionic character ?
(a) tin (IV) chloride is ionic
(b) tin (IV) chloride is hydrolysis
(c) tin (II) chloride is ionic
(d) tin (II) chloride is reducing power.
(a)
Which one of the following has no allotrope ?
(a) C
(b) Si
(c) S
(d) Pb
(d)
Why does Ge used as IR window ?
(a) Ge is semi conductor
(b) Ge is soft semi metal
(c) Ge is transparent in visible light
(d) Ge is transparent in IR
(d)
Pb is commonly inert due to
(a) layer of Pb(OH)2 and PbCO3 forms on the surface of Pb in presence of air
(b) layer of PbO forms on the surface of air
(c) layer of PbO and Pb(OH)2 forms on the surface of Pb.
(d) layer of PbO2 and Pb(OH)2 forms on the surface of Pb
(a)
Who discovered Ge ?
(a) Charles Martin Hall
(b) Paul Heroult
(c) C.A. Winkler
(d) Henry Moission
(c)
Dr. Vikram Panchal/11th Science / Chemistry(52-E)
Page 13
163.
Ans
164.
Ans
The co-ordination no. of Si in [SiF5]-1 and [SiF6]-2 is respectively
(a) 4 and 4
(b) 4 and 6
(c) 6 and 5
(d)
Which one of the following act as reducing agent ?
(a) Sn
(b) SnCl2 H2O
(c) dry SnCl2
(c)
(d) 5 and 6
(d) SnCl4
Section-B
70.
A.
71.
A.
72.
A.
73.
A.
74.
A.
75.
A.
76.
A.
77.
A.
78.
A.
79.
A.
80.
A.
81.
A.
82.
What is the characteristic of p-block ?
All non-metals and metalloid are present in p-block.
How will you get oxidation state of elements of a particular group ?
The value of maximum oxidation state of these elements is obtained by subtracting 10
from its group number.
State the % of boron in earth crust ?
The abundance of boron in earth’s crust is less than 0.0001 % by weight.
Mention the places where Boron is available.
The Boron is found in California (USA), in Turkey. While in India it is found in Puga
valley (Ladakh), Sambhar lake of Rajasthan.
State first three elements in earth’s crust.
The first is Oxygen (45.5 % by weight)
The second is Silicon (27,7 % by weight) and
The third is Alluminium (8.3 % by weight).
Why does metallic character decreases from Al to Tl of group 13 ?
The reduction potential values go on increasing from Al to Tl, so the values of electro
positively decreases.
Which one of the group 13 elements shows maximum metallic character ?
Al elements of group 13 shows maximum metallic character.
Which one of the group 13 elements has highest boiling point ?
The Boron has highest boiling point (2453 K).
Which one of the group 13 elements has least boiling point ?
The Gallium has minimum boiling point (303 K).
State the density of group 13.
B
Al
Ga
In
Tl
2.35
2.7
5.9 7.31 11.85 gm/cm3
Mention the Ered (M+3/M) of group 13.
Al
Ga
In
Tl
+3
E (M /M)
-1.66 -0.56 -0.34 +1.26
The reducing power from Al to Tl decreases, Why ?
From Al to Tl the value of Ered increases therefore reducing power decreases.
Write Chemical reaction between GaH3 and NH3.
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A.
83.
A.
84.
A.
85.
A.
86.
A.
87.
A.
88.
A.
89.
A.
90.
A.
91.
A.
92.
A.
93.
A.
94.
A.
95.
A.
96.
A.
97.
H3N + GaH3  [H3NGaH3]
Why does AlCl3 exists in dimer in vapour state ?
In vapour form AlCl3 exists in dimer form due to bridging of chlorine atoms.
State that B to Tl metallic character increases.
Metal oxides are basic and non-metal oxides are acidic.

B2O3, B(OH)3 - Acidic
Al2O3, Ga2O3, Al(OH)3, Ga(OH)3 - Amphoteric
In2O3, Tl2O3 - Basic
Why does complex of Boron is tetrahedral ?
There is no d orbital available in outermost shell of B, so that it cannot form more than
four bonds, and gives tetrahedral complex.
What is Mordant ?
Some metal ions are added to dye solution which makes it fast on fabric due to bond
formation is known as mordant.
How does Boron differ from its group members with reference to halide ?
BX3 is monomeric while other MX3 are dimeric or polymeric.
Compare Boron with diamond on the basis of hardness.
Boron is very hard and it is second hardest element after diamond.
Give the combustion reaction of Boron in nitrogen.

2B + N2  2BN (Boron Nitride)
Mention the structure of BN.
BN is soft solid with two dimensional network structure like graphite.
Write reaction between B and S.
1200 C
2B + 3S  B2S3
Write reaction between B and NH3.
high temp.
2B + 2NH3  2BN + 3H2
What is called impure state of Borax ?
The impure form of Borax is known as Tincal.
Mention the places of abundance of borax.
Borax is found in dry lakes of India, Tibet, Sri lanka and California.
Give reaction between Colemanite and Na2CO3.

Ca2B5O11 + 2Na2CO3  2CaCO3 + Na2B4O7 + 2NaBO2
How does sodium meta borate obtained ?

4NaBO2 + CO2  Na2B4O7 + Na2CO3
How does borax bead prepared ?
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A.
98.
A.
99.
A.
100.
A.
101.
A.
102.
A.
103.
A.
104.
A.
105.
A.
106.
A.
107.
A.
On heating borax, due to its decomposition swells and loses water of crystallization and
becomes anhydrous, on further heating it melts and forms glassy, transparent bead known
as borax bead.
Write molecular formula of borax bead with Ni+2, Co+2, Cr+2, Cu+2 and Mn+2.
Ni (BO2)2
Nickel borate
Co (BO2)2
Cobalt borate
Cr (BO2)3
Chromium borate
Cu (BO2)2
Copper borate
Mn (BO2)2
Manganese borate
Why does borax used on medicinal soap ?
Borax possess antiseptic property and therefore it is used in medicinal soap.
Explain the Basicity of boric acid.
H3BO3 = B(OH)3 in which 2pz orbital is empty, so Boron accept OH-1 and release H+
from water. Thus boric acid is monobasic.
B(OH)3 + H+OH-  [B(OH)4]-1 + H+
Draw the structure of boric acid.
Draw the structure of Borazene.
Why does Boron is used as control rod in nuclear reactor ?
10
B isotope can absorb neutron, therefore it is used as control rod in nuclear reactor.
Which is used for preparation of Pyrex glass ?
Borax and boric acid are used for preparation of heat resistance Borosilicate Pyrex glass.
Which is used in preparation of porcelain enamel ?
Borax is used in preparation of porcelain enamel.
Why does Al become passive ?
Al immediately reacts with air and form insoluble layer of Al2O3.
How does Cr or Mn extracted using Al ?
Aluminothermite
Cr2O3 + 2Al  2Cr + Al2O3
Process
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108.
A.
109.
A.
110.
A.
111.
A.
112.
A.
113.
A.
114.
A.
115.
A.
116.
A.
117.
A.
121.
A.
122.
A.
123.
A.
124.
Aluminothermite
Mn2O3 + 2Al  2Mn + Al2O3
Process
Which metal can be alloyed with Al ?
Al can be alloyed with Cu, Mn, Mg, Si and Zn.
Why does Al give no reaction with HNO3?
There is already passive layer of Al2O3 on the surface of Al, so that HNO3 cannot reacts
with Al.
What is meant by binary compounds ?
The inorganic compounds of carbon with metals, semi-metals and non-metals are known
as binary compound.
Which have Si as an important compound ?
Si is an important component used in ceramics, glass and cement.
How does Ge obtained ?
Ge occurs as a trace element and is mainly recovered from the flue dust arising from
rousting of Zn ores.
Mention the abundance of group 14 elements ?
Si
27.7 %
Ge
trace amount
Sn
12 ppm
Pb
13 ppm
Mention the density of diamond and graphite ?
Diamond
3.51 gm/cm3
Graphite
2.21 gm/cm3
Why does tin becomes dull in winter?
If atmospheric temperature is below 286 K then white tin is converted into gray tin.
Give examples in which co-ordination of group 14 elements would be greater than 4.
[Si F5]-1, [Si F6]-2 and [Pb Cl6]-2
What is meant by p-p bond ?
When two p orbitals of different atoms go for lateral overlapping then they form p-p
bond.
Give reaction which shows Sn+2 as reducing agent.
2Fe3+
+
Sn2+  Sn+4 + 2Fe2+
Give crystallization of chloride of tin.
SnCl2 is obtained by dissolving Sn in conc. HCl. On cooling this solution, SnCl2
crystallizes in form of SnCl2 2H2O.
Give information about structure of SiO2.
In SiO2 each Si atom is covalently bonded to four oxygen atoms and Si combines with
oxygen atoms tetrahedrally.
Give minerals of SiO2.
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A.
125.
A.
126.
A.
127.
A.
128.
A.
129.
A.
130.
A.
131.
A.
132.
A.
133.
A.
134.
A.
135.
A.
136.
A.
137.
A.
138.
A.
Quartz, Crystobalite and Tridymite are minerals of SiO2.
How does silica gel prepared ?
Silica gel is obtained by acidification of sodium silicate.
How does SnO2 prepared ?
SnO2 is prepared by heating Sn and O2 or by reaction of Sn with conc.HNO3.
Give name of Pb3O4.
Pb3O4 – Plumbo Plumbic oxide.
How does Pb3O4 prepared ?
773 K air
3PbO  Pb3O4 (2PbO, PbO2)
reverberatory furnace
How does carbon differ in  bond formation from other elements ?
Carbon forms p-p bond with carbon or other atoms while other elements of group 14
form p-p as well d-p bonds.
Which type of arrangement is appearing in diamond ?
In diamond one carbon is attached to four other carbons and form three dimensional
network structure.
Give C – C bond length in diamond.
C – C bond length in diamond is 154 pm.
State C – C bond length and distance between layers of graphite.
C – C bond length in graphite is 141.5 pm, while inert layer distance is 340 pm.
Why does graphite so soft ?
The inert layer distance in graphite is 340 pm, so there will be weak van der waals force
existing between layers and these layers easily slide over the other. Therefore graphite is
very soft.
How does fullerene looks like ?
The crystalline form of carbon is made up of porous cage like molecules.
How does fullerene prepared ?
Crystalline fullerene was first prepared by evaporation of graphite using lasers but
presently preparation involves the heating of graphite in an electric arc in the presence of
an inert gas.
Why does fullerene shows aromatic character ?
All carbons are equivalent in fullerene. Each carbon combines with other three carbon
with  bond. The remaining electron forms  bond and hence, the  bond electron gets
delocalized in M.O with gives aromatic character in fullerene.
Give C – C bond length in fullerene.
C – C bond length is 143.5 pm and C = C bond length in fullerene is 138.5 pm.
Why does fullerene shows smoothness ?
Fullerene are the only pure forms of carbon because they have no dangling bond so
possess smooth structure.
Dr. Vikram Panchal/11th Science / Chemistry(52-E)
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139.
A
140.
A.
141.
A.
142.
Why does Charcoal possess adsorption property ?
Charcoal is porous, hence it possesses the adsorption property.
Give information about solubility of crystalline allotropes of carbon.
Diamond and graphite are insoluble in liquid solvent, while fullerene is soluble in
suitable solvent.
How does artificial tannin prepared ?
When charcoal is heated with hot and dil.HNO3, it slowly dissolves and gives brown
substances which is known as artificial tannin.
Give the structure of mellitic acid.
COOH
HOOC
COOH
HOOC
COOH
COOH
benzene hexacarboxylic acid
143.
A.
How does CO behave as poison ?
CO is highly toxic in nature because it forms stable complex with hemoglobin present in
blood and stops the oxygen carrying capacity of the blood, hence it causes death.
144. Define : Ligand.
A.
The negative ion or neutral molecule which donate electron pair to the central metal for
co-ordinate covalent bond is known as ligand.
145. What type of CO ligand is ?
A.
CO is a very strong ligand.
146. Give the structure formula of [Ni(CO)4].
A.
147.
A.
Give the structure formula of [Fe(CO)5].
148.
How does dry ice prepared ?
Dr. Vikram Panchal/11th Science / Chemistry(52-E)
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A.
149.
A.
150.
A.
151.
A.
152.
A.
153.
A.
154.
A.
155.
A.
156.
A.
At room temperature and 50 to 60 atmospheric pressure CO2 gas can be liquefied, when
liquid CO2 is allowed to evaporate rapidly i.e. expands rapidly, it is converted into solid
which is known as dry ice.
What is litmus effect of CO2 ?
CO2 turns blue litmus to red,
What is meant by photosynthesis ?
In the presence of sunlight and chlorophyll of green plants, CO2 reacts with water to form
glucose. This reaction is called photosynthetic.
Why does pH of blood maintained ?
To control the pH of blood CO2 gas is used in carbonic acid buffer system.
What is meant by piezo electricity ?
A substance which experience pressure and on applying pressure or mechanical stress, it
starts conducting current is known as piezo electricity.
What is meant by adsorbent ?
A substance whose surface is available for adsorption is known as adsorbent.
Explain U.V. spectrophotometer.
A transparent solution of a given sample is prepared and filled in a cell made up of
quartz. The U.V. radiation of definite wavelength are allowed passed through solution, so
that some light would be absorbed and some would be transmit which can be measured
by detector and from which we get some information about structural formula of a given
sample.
What is meant by chromatography ?
A method of separation of mixture by using adsorption phenomenon is known as
chromatography.
How does Alumino silicate prepared ?
In a three dimensional structure of SiO2, Si+4 is partially substituted by Al+3 which gives
alumino silicate.
Section-C
25. Write electron configuration of group 13 elements.
Ans: 5B [He] 2s2 2p1
2
1
13Al [Ne] 3s 3p
10
2
1
31Ga [Ar] 3d 4s 4p
10
2
1
49In [Kr] 4d 5s 5p
14
10
2
1
81Tl [xe] 4f 5d 6s 6p
26. Why does atomic radius of Ga is less than that of Al.?
Ans: Al=143 pm
Ga=135 pm
The atomic radius of Al is more than atomic radius of Ga because there is no d orbital in
electronic configuration of Al while there is d orbital in electronic configuration of Ga. As
Dr. Vikram Panchal/11th Science / Chemistry(52-E)
Page 20
the d orbital are large in size, hence the magnitude of screening effect decreases with nucleus
by electrons present in them. Now the nucleur charge of gallium is high; as a result the
attraction towards the nucleus by outermost orbital electron increases. Hence, atomic radius of
Ga is less than that of Al.
27. Why does ionization enthalpy of Ga is more than that of Al?
Ans: Al=577kJ/mol
Ga=578KJ/mol
The first ionization enthalpy of Ga is little more compared to Al because in Ga the addition of
new valence shell and also presence of 3d orbital, which decreases the screening effect. This
means it does not remain more effective so in Ga the attractive forces of electron towards the
nucleus increases and hence, the first ionization enthalpy is little more.
28. Discuss metallic properties of group 13 elements.
Ans: The elements of group 13 show variation in metallic character. The metallic character is
higher in Al than that of B. So Al is good conductor of heat and electricity. The reduction
potential values go on increasing from Al to Tl, so the values of electro positivity decreases
as a result, metallic character decreases. Thus, B is non-metal, while Al is metal and in
Indium, Ga and Tl the metallic character decreases successively. So Tl possesses nonmetallic character.
29. Discuss Boiling point and melting point of group 13 elements.
Ans.: The elements of group 13 show irregular trends in melting point, viz the melting point
of B is the highest, while melting point of Al is low and melting point of Ga is the lowest;
the melting point of In is more than that of Ga and Tl has little more. The order of melting
points of group 13 elements are in order B> Al> Ga<In <Tl. The crystal structure of element
is responsible for this. The boiling points of the elements of group 13 on moving down the
group show regular trend. As the atomic number goes on increasing the boiling point
decreases regularly.
30. Discuss density of group 13 elements.
Ans.: The density goes on increasing as the atomic number increases for the elements of
group13 because as the atomic number increases the volume increases but the increase in
atomic mass is more compared to volume and hence, density increases.
31. Write a note on hydrides of group 13.
Ans.: Elements of group 13 do not combine directly with dihydrogen but they combine indirectly
with dihydrogen to form hydride compounds. E.g., Boron hydride is obtained by reaction of BF3
with LiH.
450K
2BF3 + 6LiH
B2H6 + 6LiF
Boron forms number of hydrides, most of hydrides having molecular formula, Bn Hn + 4 and
Bn Hn+6 which is known as Borane. Other hydride elements are polymeric. E.g; (AlH3)n, (GaH3)n
and (InH3)n their structure contains M…….H…….M bridge (M=Al, Ga, In). The stability of
hydrides decreases with increasing atomic number and so thalium hydride is quite unstable.
These hydrides are Lewis acids which readily combine with strong Lewis base (B:).
Dr. Vikram Panchal/11th Science / Chemistry(52-E)
Page 21
B: + MH3
[ B → MH3 ] (M= Al or Ga)
In addition to these polymeric hydrides, Al or Ga also form complex tetrahydrides e.g.
Tetrahydro aluminate ( III). This is known as lithium aluminium hydride, which
can be obtained by the reaction of LiH and AlCl3 in presence of dry ether.
Dry ether
4LiH + AlCl3
Li+[AlH4]- + 3LiCl
Particularly in organic reaction LiAlH4 is used as a reducing agent.
32. Write a note on halide compounds of group 13.
Ans.: Elements of group 13 form MX3 type trihalides where X= F, Cl, Br and I. TlI3 is
unknown. Due to small size and high ionization enthalpy boron atom has tendency to form
covalent bond by sp2 hybridisation and form trihalide. The trihalides BX3 act as Lewis acid and
the order of its strength is BI3 > BBr3 >BCl3> BF3. In vapour form AlCl3 exists in dimer form
due to bridging of chlorine atoms and its structure is as shown in figure.
Structure of Al2Cl6 (dimer) (gaseous state)
AlCl3 is Lewis acid. BF3 and AlCl3 are strong Lewis acids and therefore used as a catalyst in
Friedel and Crafts alkylation reaction and electrophilic aromatic substitution reaction.
Ga and Tl also form MX type halides where M= Cl, Br, I. The stability of MX type halide
increases as the atomic number increases, so that TlX is more stable than GaX.
33. Discuss oxides and hydroxides compounds of group 13.
Ans. The group 13 elements form oxides having formula M2O3 and hydroxide having formula
M(OH)3. As the atomic number of element goes on increasing the acidic character of oxide and
the hydroxide decreases, and at the same time the basic character goes on increasing. E.g. oxide
and hydroxide of boron are acidic, those of Al and Ga are amphoteric and In are basic while
those of Tl are strong base.
34.Explain complex and double salts of group 13.
Ans.: In elements of group 13, in the electronic configuration of boron the d-orbital is absent, so
it forms only tetrahedral complex like [BH4]- , [BI4]-, etc. The electronic configuration of Al, Ga,
In and Tl have d-orbital (in Al it is form of 3d0), so they form octahedral complexes like [AlF6]3-,
[GaCl6]3-,[InCl6]3-, and [TlCl6]3-, with octahedral aqua ions can be described as [M(H2O)6]3+, (
where M=Al, Ga, In and Tl). Aluminium sulphate reacts with sulphate of NH4+ and alkali metal
ions and form double salts known as alums with formula M2SO4 . Al2(SO4)3 . 24H2O or
MAl(SO4)2 . 12H2O ( where M= Na+, K+, Rb+ and NH4+ ).The uses of this double salts are to be
convert hard water to soft water and as a mordant in chemicals of colour dye.
35. Give physical properties of boron.
Ans.: i.
Boron is extremely hard substance. In order of hardness, it comes next to
Dr. Vikram Panchal/11th Science / Chemistry(52-E)
Page 22
diamond.
ii. The melting point and boiling point of boron are very high.
iii. Boron is poor conductor of heat and electricity.
iv. Boron has two isotopes 10B and 11B and its relative abundance is 20% and 80%
respectively
.
v. Boron has two allotropes. The colour of amorphous form is dark brown whereas
the crystalline form is found in black metallic luster.
36. Write equations of Boron with non-metals.
Ans.: Non-metal dinitrogen, dioxygen and dihalogen react with boron at high temperature.
4B + 3O2
2 B2O3
2B + N2
2 BN
2B + 3X2
2 BX3, (X=Cl,Br,I)
37. Write equations of Boron with acid.
Ans.:
2B + 3H2SO4
2 H3BO3 + 3SO2
B + 3HNO3
H3BO3 + 3NO2
38.Write equations of Boron with alkali.
Ans.:
2B + 6NaOH(l)
2 Na3BO3 + 3H2
Sodium borate
2B + 6KOH(l)
2 K3BO3
+ 3H2
Potassium borate
39. Explain reaction of Boron with metals.
Ans.: Boron reacts with some metals on heating and converts into borides which are very hard
and solid substance having high melting point, e.g;
B + Cr
CrB (Chromium boride)
40.Explain preparation of diborane.
Ans.: In the laboratory, diborane is prepared by the reaction of iodine with sodium-borohydride
in the presence of polyether as a solvent.
polyether
2NaBH4 + I2
B2H6 + 2NaI + H2
On an industrial scale, diborane is obtained by the reaction of boron triflouride or boron
trichloride with lithium iodide at 450K temperature.
450 K
2BF3 + 6LiH
B2H6 + 6LiF
450 K
2BCl3 + 6LiH
B2H6 + 6LiCl
41. Explain properties of diborane.
Ans.: i. Diborane is colourless and highly toxic gas.
ii. Diborane has strong affinity for O2 and therefore it catches fire spontaneously on
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exposure to air and releases energy. The heat of combustion is very high.
B2H6 + 3O2
B2O3 + 3H2O
∆H= -2008 kJ mol-1
iii. At 450 K temperature, if diborane is heated with NH3, forms Borazine (B3N3H6)
having structure like benzene and hence it is also called inorganic benzene.
450 K
3B2H6 + 6NH3
2B3N3H6 + 12H2
iv. Diborane on hydrolysis gives boric acid and liberates H2 gas.
B2H6 + 6H2O → 2H3BO3 + 6H2
v. The structure of diborane is given in figure.
42. Write properties of Aluminium.
Ans.: i. Aluminium is a soft, silvery white metal.
ii. It has high tensile strength, high electrical and thermal conductivity. (twice than that
of Cu).
iii. It is highly electropositive.
iv. It readily reacts with O2 and forms a protective layer of Al2O3 on its surface, which
makes it passive.
43. Give uses of Aluminium.
Ans.: i. Aluminium is used extensively in industries and in daily life.
ii. It forms useful alloys with Cu, Mn, Mg, Si, and Zn.
iii. Al and its alloys are used in making utensils, aeroplane parts and also in some
preparations.
iv. It is used in Aluminothermite process for obtaining the chromium and manganese
metals from their oxides.
v. Aluminium is used as a strong reducing agent.
44.Give equations of Al with acid and base.
Ans.:
Reaction with Acid:
2Al + 6HCl + 12H2O
2[Al(H2O)6]Cl3 + 3H2
2Al + 6H2SO4
Al2(SO4)3 + 3SO2 + 6H2O
Reaction with base:
2Al + 2NaOH + 6H2O
2Na[Al(OH)4] + 3H2
45. Write a note on ionization enthalpy of group 14.
Ans.: On moving down in the group 14 as the atomic number increases, the order of change one
notices in ionization enthalpy is C > Si > Ge > Sn < Pb. From C to Sn as the atomic number
increases the atomic size also increases and hence ionization enthalpy decreases but instead of
decreasing the ionization enthalpy of Pb slightly increases because of the intervening of d and f
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both types of orbitals in electronic configuration of Pb. So the force of attraction towards the
nucleus increases due to poor shielding effect of that orbital and hence, ionization enthalpy
decreases.
46. Write a note on diamond.
Ans.: Due to sp3 hybridisation in carbon, it combines with other four carbon atoms by single
covalent bonds. The bonded four carbons are arranged towards the corner of the tetrahedron as
shown in figure. Each carbon atom, due to sp3 hybridisation joins with other four carbon atoms
by single covalent bond and forms three dimensional network structure. The distance between
two carbon atoms is 154 pm. All the carbon atoms are bound to each other by covalent bonding
and these bonds are very strong. So diamond is extremely hard solid substance.
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