NCERT Class 11 Chemistry Chapter 11 Some P Block Elements Multiple Choice Questions

NCERT Solutions For Class 11 Chemistry Chapter 11 Some P Block Elements Multiple Choice Questions

Question 1. Which of the following metals has the largest abundance in the earth’s crust

1. Aluminium
2. Magnesium
3. Calcium
4. Sodium

Answer: 1. Aluminium

Question 2. For BCl₃, AlCl₃ and GaCl3 the increasing order of ionic character is

1. BCl₃ < AlCl₃< GaCl₃
2. GaCl₃ < AlCl₃ < BCl₃
3. BCl₃< GaCl₃< AlCl₃
4. AlCl₃ < BCl₃ < GaCl₃

Answer: 3.  BCl₃< GaCl₃< AlCl₃

The ionic character of a compound depends on the polarising power of the cation present in it. The more the polarising power of the cation, the less the ionic character of the compound containing the cation. The polarising power of the cations B⁺³, Al⁺³ and Ga⁺³ is Al⁺³ < Ga⁺³ < B⁺³. Hence, the increasing order of ionic character will be BCl₃ < GaCl₃< AlCl₃

Question 3. In borax, the number of B- O- B link and B- OH bonds present are respectively

1. Five and four
2. Four and five
3. Three and four
4. Five and five

Answer: 1. Five and four

Question 4. In diborane, the number of electrons that account for bonding in the bridges is

1. Six
2. Two
3. Eight
4. Four

Answer: 4. Four

Two bridging bonds are present in diborane. In the bridges, each H-atom is bonded to two B-atoms by sharing of only one pair of electrons i.e., 3c-2e bonds. Thus, the total number ofelectrons for two bridges is four.

Question 5. The main reason that SiCl4 is easily hydrolysed as compared to CCl₄ is that

1. SiCl bond is weaker than C — Cl bond
2. SiCl₄ can form hydrogen bonds
3. SiCl₄ is covalent
4. Si can extend its coordination number beyond four

Answer: 4. Si can extend its coordination number beyond four

In SiCl₄ , Si has a vacant d -orbital. Therefore, it can expand its coordination through coordinate bonding to get hydrolysed

Question 6. Which ofthe following ions cannot be formed by boron

1. BF^3-₆
2. BH^–₄
3. B(OH)^–₄
4. BO^–₂

Answer: 1. BF^3-₆

Boron cannot expand its covalency beyond four due to the unavailability of π-orbitals. Thus it cannot form BF^3-_6.

Question 7. Which of the following exists as covalent crystals in the solid state

1. Phosphorus
2. Iodine
3. Silicon
4. Sulphuric

Answer: 3. Silicon

Silicon exists as covalent crystals in a solid state

Question 8. Which of the following are Lewis acids

1. PH₆ and SiCl₄
2. BCl₃ and AlCl₃
3. PH₃ and BC
4. AlCl₃ and SiCl₄

Answer: 2. BCl₃ and AlCl₃

Both BCl₃ and AlCl₃ have incomplete octets around the central atom. Thus they can act as Lewis acids.

Question 9. Which of the following oxides is amphoteric

1. SnO₂
2. CaO
3. SiO₂
4. CO₂

Answer: 1. SnO₂

SnO₂ reacts with both acids as well as with bases. Hence, it is an amphoteric oxide

SnO₂ + 4HCl→SnCl₂+ 2H₂O

SnO₂ + 2NaOH→Na₂SnO₃+ H₂O

Question 10. Which of the following statements is incorrect—

1. Pure sodium dissolves in liquid ammonia to give a blue solution
2. NaOH reacts with glass to give sodium silicate
3. Aluminium reacts with excess NaOH to give Al(OH)₃
4. NaHCO₃ on heating gives Na₂CO₃

Answer: 3. Aluminium reacts with excess NaOH to give Al(OH)₃

Aluminium reacts with NaOH to form sodium metaaluminate (NaAlO₂).

Question 11. Name the two types ofthe structure of silicate in which one oxygen atom of [SiO₄]^4- is shared

1. Linear chain silicate
2. Sheet silicate
3. Borosilicate
4. Three-dimensional

Answer: 3.  Pyrosilicate

Question 12. Which of these is least likely to act as a Lewis base

1. BF₃
2. PF
3. CO
4. F

Answer: 1. BF₃

BF₃ is a Lewis acid

Question 13. Which ofthe following is electron-deficient

1. (BH₃)₂
2. PH₃c
3. (CH₃)₂
4. (SiH₃)₂

Answer: 1. (BH₃)₂

Boron hydrides are electron-deficient compounds

Question 14. Number of carbon atoms per unit cell of diamond unit cell

1. 1
2. 4
3. 8
4. 6

Answer: 2. 4

Diamond exists as a face-centred cubic unit cell. Thus, at the centre of each face one atom is present i.e., ½ × 6 = 3 atoms. Also, ½ × 8 = 1 atom is present at the comers. Hence, the total no. of atoms per unit cell = 3 +1 = 4 atoms.

Question 15. . Which of these is not a monomer for a high molecular mass silicone polymer 

1. PhSiCl₃
2. MeSiCl₃
3. Me₂SiCl₂
4. Me₃SiCl

Answer: 4. Me₃SiCl

Polymerisation involves the repeating of monomeric units. If Me3 SiCl units are joined, then a dimer is formed rather than a polymer.

Question 16. Which ofthe following structures is similar to graphite

1. B₂H₆
2. BN
3. B
4. B₄C

Answer: 2. BN

Question 17. The basic structural unit of silicate is

1. SiO^2-₄
2. SiO^–
3. SiO^4-₄
4. SiO^2-₃

Answer: 3.SiO^4-₄

Question 18. The stability of the +1 oxidation state among Al, Ga, In and Tl increases in the sequence

1. Ga<In<Al<Tl
2. Al < Ga < In < Tl
3. Tl < In < Ga < A1
4. In <T1 < Ga < Al

Answer: 2. Al < Ga < In < Tl

Question 19. AlF₃ is soluble In HF only In the presence of HF. It is due to the formation of

1. K₃(AlF₆)
2. AlH₃
3. K₃(AlF₃H)
4. K₃(AlF₃H₃)

Answer: 1. K₃(AlF₆)

The maximum coordination number shown by AF₆^3- is 6 and thus it can form A1F|- ion.

Question 20. Boric acid is an acid because its molecule

1. Gives up a proton
2. Accepts OH from water releasing a proton
3. Combines with a proton from the water molecule
4. Contains replaceable H -ion

Answer: 2. Accepts OH from water releasing a proton

H₃BO₃ is a Lewis acid and it takes up OH ion giving up H ion in the solution.

Question 21. It is because of the inability of ns² electrons of the valence shell to participate in bonding that

1. Sn²⁺ is oxidising while Pb⁴⁺ is reducing
2. Sn²⁺ and Pb⁴⁺ are both oxidising and reducing
3. Sn⁴⁺ is reducing while Pb⁴⁺ is oxidising
4. Sn²⁺ is reducing while Pb⁴⁺ is oxidising

Answer: 4.  Sn²⁺ is reducing while Pb⁴⁺ is oxidising

The inert pair effect increases down the group. Hence Sn²⁺ acts as a reducing agent whereas Pb⁴⁺ is an oxidising agent

Question 22. Which one of die following elements is unable to form MF₆^3- ion

1. In
2. Ga
3. B
4. Al

Answer: 3.  B

Boron does not have any vacant orbital. Therefore it cannot expand its coordination more than 4. Thus it is unable to form a compound ofthe type MF₆^3-

Question 23. The correct order of atomic radii in group 13 elements is

1. B < Ga < Al < In < Tl
2. B < Al < In < Ga < Tl
3. B < Ga < Al < Tl < In
4. B < Al < Ga < In < Tl

Answer: 1. B < Ga < Al < In < Tl

Due to the weak screening effect of d -d-orbital, the atomic radius of Ga is less than that of AI.

Question 24. The wrong statement about fullerene is

1. It has 5-membered carbon ring
2. It has 6-membered carbon ring
3. It has sp² hybridisation
4. It has 5-membered rings more than 6-membered rings

Answer: 4. It has 5-membered rings more than 6-membered rings

Fullerene consists of 12 five-membered rings and 20 six-membered rings. So it has five-membered rings less than six-membered rings

Question 25. Iodine oxidises sodium borohydride to give

1. B₂H₆
2. Sodium hydride
3. HI
4. I^–₃

Answer: 1. B₂H₆

The oxidation of sodium borohydride with iodine in diglyme gives diborane.

Question 26. Which material is used as a neutron moderator

1. Graphite
2. Boron
3. Cadmium
4. Uranium

Answer: 1. Graphite

Neutron moderators slow down the speed of neutrons by collisions. They do not absorb neutrons. For

Example:  Water and graphite

Question 27. For silicon which is not correct

1. It is a type of silicate
2. It is hydrophilic
3. It is thermally unstable
4. The repeating unit is R₂SiO

Answer: 3. Silicon is hydrophobic

Question 28. Which ofthe following is not sp² -hybridised

1. Graphite
2. Graphene
3. Fullerene
4. Dry ice

Answer: 4. Dry ice

Solid CO₂ is dry ice in which carbon atom undergoes sp -hybridization

Question 29. The pair of amphoteric hydroxides is

1. Be(OH)₂, Al(OH)₃
2. Al(OH)₃,LiOH
3. B(OH)₃,Be(OH)₂
4. Be(OH)₂, Mg(OH)₂

Answer: 1. Be(OH)₂, Al(OH)₃

Al and Be show similar properties due to their diagonal relationship

Question 30. Which ofthe following reactions do not take place

BF₃ + F^–→BF₄^– …………..(1)

BF₃ + 3F^–→BF₄^3-…………..(2)

AlF₃ + 3F^–→AlF^3-₆ ………….(3)

1. Only 1
2. Only 2
3. Only 3
4. Only 1 and 3

Answer: 2. Only 2

BF₃ forms complex halides of the type BF^–₄ in which the B atom has coordination number 4. It cannot extend its coordination number beyond 4 due to the unavailability of d -d-orbitals in its configuration. Hence, BFg ion (sp³d³ hybridisation) is not formed. On the other hand, AI can extend its coordination number beyond 4 due to the availability of d -d-orbitals in its configuration.

Question 31. Select the correct options from the following

1. Graphene is an atomic layer of graphite.
2. Graphene is an atomic layer composed of sp² – hybridised carbon.
3. Chemical bonds in graphite are similar in strength to that of diamond.
4. All of these.

Answer: 4. All of these.

Question 32. Among the following substituted silanes, the one which will give rise to cross-linked silicone polymer on hydrolysis is

1. R₃SiCl
2. R₃SiCl
3. RSiCl₃
4. R₃SiCl

Answer: 3. RSiCl₃

Question 33. Hydride of boron occurs as B2H6 but B2C16 does not exist This is because

1. pπ-dπ back bonding is possible in B₂H₆ but not in R₂SiCl₂
2. Boron and hydrogen have almost equal values of electronegativity
3. Boron and chlorine have almost equal atomic sizes
4. Small hydrogen atoms can easily fit in between boron atoms but large chlorine atoms do not.

Answer: 1. pπ-dπ back bonding is possible in B₂H₆ but not in R₂SiCl₂

Question 34. Which of the given compounds does not react with dilute HC1 at high temperature

1. SnSO₄
2. PbSO₄
3. BiOCl
4. CdSO₄

Answer: 2. PbSO₄

PbSO₄ belongs to group I so, it is insoluble in HCl. Acidity increases with the addition of ethylene glycol. It also exhibits a 3D arrangement due to hydrogen bonding.

Question 35. Boric acid is a weak acid, but in the presence of which ofthe following compounds, it behaves as a stronger acid

1. Glycerol
2. Acetic acid
3. Ethanol
4. Ethylene

Answer: 1. Glycerol

Question 36. The structure of diborane (B₂H₆) contains—

1. Four 2c-2e bonds and four 3c-2e bonds
2. Two 2c-2e bonds and two 3c-3e bonds
3. Two 2c-2e bonds and four 3c-2e bonds
4. Four 2c-2e bonds and two 3c-2e bonds

Answer: 4. Four 2c-2e bonds and two 3c-2e bonds

Question 37. Which of the following elements is used in high-temperature thermometry

1. Al
2. Ga
3. Hg
4. In

Answer: 2. Ga

Question 38. An important ingredient of Pyrex glass is—

1. Zn
2. Pb
3. B
4. Fe

Answer: 3. B

Question 39. Which ofthe following is the purest allotrope of carbon

1. Diamond
2. Fullerene
3. Graphite
4. Charcoal

Answer: 2. Fullerene

Question 40. The number of isomers possible for disubstituted borazine, B₃N₃H₄X₂ is-

1. 3
2. 4
3. 5
4. 6

Answer: 2. 4

Question 41. Pentaborane-9 (B₅H₉) is an example of

1. Arachno-borane
2. Pseudo-borane
3. Nido-borane
4. Close-borane

Answer: 1. Arachno-borane

Question 42. So when reacts with A forms B. A & B respectively are

1. HF, H₂SiF₄
2. HF, H₂SiF₆
3. HCl, H₂SiCl6
4. HI, H₂SiI₆

Answer: 2. HF, H₂SiF₆

Question 43. Boric acid is a

1. Monobasic and weak Lewis acid
2. Monobasic and weak Bronsted acid
3. Monobasic and strong Lewis acid
4. Tribasic and weak Bronsted acid

Answer: 1. Monobasic and weak Lewis acid

Question 44. Which ofthe following does not exist in a free state

1. BF₃
2. BCl₃
3. BBr₃
4. BH₃

Answer: 4. BH₃

Question 45. The correct order of decreasing Lewis acid character is

1. BCl₃ > AlCl₃> GaCl₃ > InCl₃
2. AlCl₃ > BCl₃> InCl₃> GaCl₃
3. AlCl₃ > GaCl₃> BCl₃ > InCl₃
4. InCl₃ > GaCl₃ > AlCl₃ > BCl₃

Answer: 1. BCl₃ > AlCl₃> GaCl₃ > InCl₃

Question 46. Which of the following is present in the chain structure of silicate

1. (Si₂O^2-₅)_n
2. (Si₂O^2-₃)_n
3. Si₂O^4-₄
4. Si₂O^6-₇

Answer: 2. (Si₂O^2-₃)_n

Question 47. A metal, M forms chlorides in +2 and +4 oxidation states. Which ofthe following statements about these chlorides is correct

1. MCl₂ is more volatile than MCl₄
2. MCl₂ is more ionic than MCl₄
3. MCl₂ is more soluble in any. ethanol than MCl₄
4. MCl₂ is more easily hydrolysed than MCl₄

Answer: 2. MCl₂ is more ionic than MCl₄

Question 48. The number of O-atoms that are shared per Si04 tetrahedra in silicate anion of beryl is

1. 4
2. 3
3. 2
4. 1

Answer: 3. 2

Question 49. Which of the following on hydrolysis produces crosslinked silicone polymer

1. R₄Si
2. RSiCl₃
3. R₂SiCl₂
4. R₃SiCl

Answer: 2. RSiCl₃

Question 50. The antidote of poisoning caused by CO is

1. Carborundum
2. Carbogen
3. Carbonic acid
4. Pure oxygen

Answer: 2. Carbogen

Question 51. Carbon suboxide in reaction with water produces

1. Oxalic acid
2. Formic acid
3. Lactic acid
4. Malonic acid

Answer: 4. Malonic acid

Question 52. The volume of which liquid metal increases on solidification

1. Ga
2. Al
3. Zn
4. Cu

Answer: 1. Ga

Question 53. Which ofthe following reacts only with alkali

1. Question B₂O₃
2. Al₂O₃
3. Ga₂O₃
4. ln₂O₃

Answer: 1. B₂O₃

Question 54. Which is the strongest Lewis acid

1. BF₃
2. BCl₃
3. BBr₃
4. BI₃

Answer: 4. BI₃

Question 55. The atomic radius of Ga is slightly less than that of Al. The reason is

1. Weaker shielding effect of s-electrons of Ga
2. Stronger shielding effect of s -electrons of Ga
3. Weaker shielding effect of d -electrons of Ga
4. Stronger shielding effect of d -electrons of Ga

Answer: 3. Weaker shielding effect of d -electrons of Ga

Question 56. Carbon does not form complexes, because

1. Vacant d -d-orbitals are absent in it
2. It is not a metal
3. Its atomic radius is small
4. It is neutral

Answer: 1.  Vacant d -d-orbitals are absent in it

Question 57. Supercritical CO₂ is used as

1. Dry ice
2. Fire extinguisher
3. A solvent for the extraction of organic compounds from natural sources
4. The inert solvent in various reactions

Answer: 3.  A solvent for the extraction of organic compounds from natural sources

Question 58. The stability of the +1 oxidation state increases in the sequence

1. Al < Ga < In < Tl
2. Tl<In<Ga<Al
3. In < Tl < Ga < Al
4. Ga<In<Al<Tl

Answer: 1. Al < Ga < In < Tl

Question 59. Which ofthe following is acidic

1. B₂O₃
2. Al₂O₃3
3. Ga₂O₃
4. ln₂O₃

Answer: 1. B₂O₃

Question 60. The correct order of first ionisation enthalpy for Gr-13 elements is

1. B > Al > Ga > In > Tl
2. B < Al < Ga < In < Tl
3. B < l> Ga < In > Tl
4. B > Al < Ga > In < Tl

Answer: 4.  B > Al < Ga > In < Tl

Question 61. Which of the following elements is not likely to be the central atom in MF^3-₆

1. B
2. Al
3. Ga
4. In

Answer: 1. B

Question 62. The tendency of catenation in Gr-14 elements follows the order

1. C > Si > Ge > Sn
2. C>Si > Ge ≈ Sn
3. Si > C > Sn > Ge
4. Ge > Sn > Si > C

Answer: 2.  C>Si > Ge ≈Sn

Question 63. The repeating structural unit in silicone is

Answer: 2.

Question 64. Which of the following allotropic forms of carbon is isomorphous with crystalline silicon

1. Graphite
2. Coal
3. Coke
4. Diamond

Answer: 4. Diamond

Question 65. The shape and hybridisation of the B-atom of BH^– ₄ is

1. Pyramidal, sp³
2. Octahedral, sp³ d²
3. Tetrahedral, sp³
4. None of these

Answer: 3.  Tetrahedral, sp³

Question 66. Germanium is transparent in—

1. Visible light
2. Infrared region
3. Ultraviolet region
4. Ultraviolet region

Answer: 2. Infrared region

Question 67. The chain length of silicone polymer can be controlled by adding

1. MeSiCl
2. Me₂SiCl₂
3. Me₃SiCl
4. Me₄Si

Answer: 3.  Me₃SiCl

Question 68. Higher B—F (in BF3) bond dissociation energy as compared to that of C— F (in CF₄ ) is due to

1. Stronger cr-bond between B and F in BF₃ as compared to that between C and F in CF₄
2. Significant pn-pn interaction between B and F in
3. BF₃ whereas there is no possibility of such interaction between C and F in CF₄
4. Lower degree of pn-pn interaction between B and F in BF₃ than that between C and F in CF₄ smaller size of B -atom as compared to that of C -atom

Answer: 2.  Significant pn-pn interaction between B and F in

Question 69. The reaction of diborane with ammonia initially gives

1. B₂H₆.NH₃
2. B₂H₆-3NH₃
3. Borazol
4. [BH₂(NH₃)₂]+[BH₄]^–

Answer: 4.  [BH₂(NH₃)₂]+[BH₄]^–

Question 70. 

X, y, Z and their respective colours are

1. X = Cu(BO₂)₂ (blue) , Y = CuBO₂ (colourless) , Z= Cu (red)
2. 2. CuBO₂(blue) , y =Cu(BO₂)₂ (colourless),Z = Cu (Black)
3. X = Cu(BO₂)₂ (red) , Y = CuBO₂ (blue) Z = (red)
4. X = Cu (red) , Y = Cu(BO₂)₂ (blue) , Z = CuBO (colourless)

Answer: 1.  X = Cu(BO₂)₂ (blue) , Y = CuBO₂ (colourless) , Z= Cu (red)

Question 71. The correct formula for borax is—

1. Na₂[B₄O₄OH)3].9H₂O
2. Na₂[B₄O₅(OH)4].8H₂O
3. Na₂[B₄O₆(OH)5].7H₂O
4. Na₂[B₄O₇(OH)6]-6H₂O

Answer: 2. Na₂[B₄O₅(OH)4].8H₂O

Question 72. Which ofthe following statements is correct

1. Sn (2) and Pb (4) salts are used as oxidants
2. Sn (2) and Pb (4) salts are used as reductants
3. Sn (2) salts are used as oxidants and Pb (4) salts are used as reductants
4. Sn (2) salts are used as reductants and Pb (4) salts are used as oxidants

Answer: 4. Sn (2) salts are used as reductants and Pb (4) salts are used as oxidants

Question 73. SiCl4 gets readily hydrolysed but CC14 does not, because

1. Si can expand its octet but C does not
2. The ionisation enthalpy of C is greater than that of Si
3. C forms both double and triple bonds
4. The electronegativity of C is greater than that of Si

Answer: 1.  Ionisation enthalpy of C is greater than that of Si

Question 74. PbCl₄ exists but PbBr₄ and Pbl₄ do not, because

1. Chlorine is a most electronegative element
2. Bromine and iodine are larger
3. Bromine and iodine cannot oxidise Pb to Pb⁴⁺
4. Bromine & iodine are stronger oxidants than chlorine

Answer: 3. Bromine and iodine cannot oxidise Pb to Pb⁴⁺

Question 75. Which of the following resembles CO in terms of physical properties

1. O₂
2. Cl₂
3. N₂
4. F₂

Answer: 3. N₂

Question 76. Which ofthe following statements is incorrect

1. Most of the silicones are water repellents
2. Silicones get dissociated at high temperature
3. Silicones do not get oxidised in air at high temperature
4. Silicones are good thermal and electrical insulators

Answer: 2. Silicones get dissociated at high temperature

Question 77. Wollastonite is a

1. Three-dimensional silicate
2. Chain silicate
3. Sheet silicate
4. Cyclic silicate

Answer: 4. Cyclic silicate

Question 78. B(OH)₃ + NaOH ⇌  NaBO₂ + Na[B(OH)₄] + H₂O; The above reaction be made to proceed in the forward direction by

1. Addition of diol
2. Addition of borax
3. Addition of KHF₂
4. Addition ofNaHPO₄

Answer: 1. Addition of diol

Question 79. Which ofthe following is correct

1. Al(OH)₃ is more acidic than B(OH)₃
2. B(OH)₃ is basic but Al(OH)₃ is amphoteric in nature
3. B(OH)₃ is acidic but Al(OH)₃ is amphoteric in nature
4. Both B(OH)₃ and Al(OH)₃ are amphoteric

Answer: 3.  B(OH)₃ is acidic but Al(OH)₃ is amphoteric in nature

Question 80. Which ofthe following is correct

1. B₂H₆-2NH₃ is known as inorganic benzene
2. Boric acid is a protonic acid
3. Be exhibits coordination number = 6
4. BeCl₃ and AlCl₃ have bridged chlorine structures in the solid phase

Answer: 4.  BeCl₃ and AlCl₃ have bridged chlorine structures in the solid phase

Question 81. B cannot form B3+ ion, because

1. Formation of B³⁺  ion requires a greater amount of energy and this cannot be obtained from lattice energy or hydration energy.
2. B is a non-metal
3. B do not possess any vacant d -orbitals
4. B possess the highest melting point among its group members

Answer: 1. Formation of B³⁺  ion requires a greater amount of energy and this cannot be obtained from lattice energy or hydration energy

Question 82. Which of the following has the minimum heat of dissociation

1. (CH₃)₃N :-→BF₃
2. (CH₃)₃N :-→B(CH₃)₂F₃
3. (CH₃)₃N :→B(CH₃)₃
4. (CH₃)₃N :→B(CH₃)F₂

Answer: 3.  (CH₃)₃N :→B(CH₃)₃

Question 83. The correct statement concerning CO is

1. It combines with H₂O to give carbonic acid
2. It reacts with haemoglobin
3. It acts only as a reducing agent
4. It cannot form adducts

Answer: 2. It reacts with haemoglobin

Question 84. Foamite mixture consists of

1. Al(SO)₃ + NaHCO
2. Al₂(SO₄)₃ + Na2CO₃
3. Fe₂(SO₄)₃ + Na2CO₃
4. CuSO₄ + NaHCO₃

Answer: 1.  Al₂(SO₄)₃ + Na2CO₃

Question 85. In which of the following compounds, the 3c-2e bond is present

1. AI₂(CH₃)₆
2. In (C₆H₅)₃
3. B₂H₆
4. AlCl

Answer: 1 and 2

Question 86. Which ofthe following oxides do not get reduced by CO 

1. ZnO
2. Fe₂O
3. CaO
4. Na₂O

Answer: 1 and 3

Question 87. Which ofthe following is not isostructural with CO₂ 

1. SnCl₂
2. HgCl₂
3. SCl₂
4. Znl₂

Answer: 2 and 4

Question 88. C(OH₄) is unstable but Si(OH)₄ is stable. Possible reasons are

1. C—O bond energy is low
2. C—O bond energy is high
3. Si—O bond energy is low
4. Si

Answer: 1 and 4

Bond energy is high

Question 89. Which ofthe following statements are correct

1. Fullerenes have dangling bonds
2. Fullerenes are cage-like molecules
3. Graphite is thermodynamically the most stable allotrope of carbon
4. Graphite is the purest allotrope of carbon

Answer: 2 and 3

Question 90. Boron trifluoride (BF₃) is

1. An electron-deficient compound
2. A Lewis acid
3. An ionic compound
4. Used as rocket fuel

Answer: 1 and 2

Question 91. Compounds which readily undergo hydrolysis are

1. AlCl₃
2. CCl₄
3. SiCl₄
4. PbCl₃

Answer: 1, 3 and 4

Question 92. Which of the following compounds undergo disproportionation in aqueous solution

1. TlCl₃
2. GaCl
3. InCl
4. TlCl

Answer: 2 and 3

Question 93. Me3SiCl is used during polymerisation of organoisilicones because

1. The chain length of organosilicon polymers can be controlled by adding Me3SiCl.
2. Me₃SiCl blocks the end terminal of the silicone polymer
3. Me₃SiCl improves the quality and yield of the polymer
4. Me₃SiCl acts as a catalyst during polymerisation

Answer: 1 and 2

Question 94. Which of the following acids, on dehydration, produce oxides of carbon

1. Succinic acid
2. Propanoic acid
3. Malonic acid
4. Formic acid

Answer: 3 and 4

Question 95. Which of the following are basic

1. B₂O₃
2. Tl₂O
3. ln₂O₃
4. Al₂O₃

Answer: 2 and 3

Question 96. The linear shape of C02 is due to

1. sp³ -hybridisation of C
2. sp -hybridisation of C
3. pπ-pπ bonding between C and O
4. sp² -hybridisation of C

Answer: 2 and 3

Question 97. Which metallic salts exhibit the same colouration both in oxidising and reducing flame in the borax-bead test

1. Fe
2. Mn
3. Co
4. Cr

Answer: 3 and 4

Question 98. Which of the following two acidic substances react to give an alkaline solution

1. H₂B₄O₇
2. H₃BO₃
3. HF
4. KHF₂

Answer: 2 and 4

Question 99. Which of the following are the ingredients of baking powder

1. NaOH
2. Tartaric acid
3. Formic acid
4. Potassium hydrogen tartrate

Answer: 2 and 4

Question 100. Which ofthe following are sheet silicates

1. Diopside
2. Kaolinite
3. Talc
4. Beryl

Answer: 2 and 3

Question 101. Identify the correct resonating structures

1. O -C ≡ O
2. O= C=O
3. O ≡ C-O⁺
4. ^–O – C≡O⁺

Answer: 2 and 4

Question 102. Which of the following species are not known

1. [SiCl₆]^2-
2. [CF₆]^2-
3. [PbCl₆]^2-
4. [SiF₆]^2-

Answer: 2 and 3

Question 103. Which of the following are correct concerning Gr-14 elements

1. Stability of dihalides: CX₂ > SiX₂ > GeX₂ > SnX₂
2. The tendency to form pn-pn multiple bonds increases down the group
3. The tendency of catenation decreases down the group
4. Each of them forms oxide ofthe type MO₂

Answer: 2, 3 and 4