CBSE Class 11 Chemistry p-Block Elements MCQs Set C

Question: Aluminium vessels should not be washed with materials containing washing soda because
a) washing soda is expensive
b) washing soda is easily decomposed
c) washing soda reacts with aluminium to form soluble aluminate
d) washing soda reacts with aluminium to form insoluble aluminium oxide
Answer: c

Question: Which of the following is most abundant in the earth crust ?
a) Boron
b) Aluminium
c) Gallium
d) Thallium
Answer: b

Question: The correct order of atomic radii in group 13 elements is
a) B < Al < In < Ga < Tl
b) B < Al < Ga < In < Tl
c) B < Ga < Al < Tl < In
d) B < Ga < Al < In < Tl 
Answer: d

Question: Which of the following types of forces bind together the carbon atoms in diamond?
a) Ionic
b) Covalent
c) Dipolar
d) van der Waals 
Answer: b

Question: Boric acid is an acid because its molecule
a) contains replaceable H⁺ ion
b) gives up a proton
c) accepts OH^– from water releasing proton
d) combines with proton from water, molecule.
Answer: c

Question: Which of the following structure is similar to graphite?
a) B4C
b) B₂H₆
c) BN
d) B 
Answer: c

Question: Thallium shows different oxidation states because
a) it is transition element
b) of inert pair effect
c) of its amphoteric character
d) of its higher reactivity
Answer: b

Question: Which of the following is an insulator?
a) Graphite
b) Aluminium
c) Diamond
d) Silicon
Answer: c

Question: The element which shows least metallic character is
a) Indium
b) Boron
c) Aluminium
d) Gallium
Answer: b

Question: Which of the following statements about H₃BO₃ is not correct?
a) It has a layer structure in which planar BO₃ units are joined by hydrogen bonds.
b) It does not act as proton donor but acts as a Lewis acid by accepting hydroxyl ion.
c) It is a strong tribasic acid.
d) It is prepared by acidifying an aqueous solution of borax.
Answer: c

Question: Which one of the following has the lowest m.p.?
a) B
b) Al
c) Ga
d) Tl
Answer: c

Question: Name the two types of the structure of silicate in which one oxygen atom of [SiO₄]^4– is shared?
a) Linear chain silicate
b) Sheet silicate
c) Pyrosilicate
d) Three dimensional
Answer: c

Question: Boron compounds behave as Lewis acids, because of their
a) ionisation property
b) electron deficient nature
c) acidic nature
d) covalent nature.
Answer: b

Question: Which metal is protected by a layer of its own oxide?
a) Al
b) Ag
c) Au
d) Fe
Answer: a

Question: Which statement is wrong?
a) Beryl is an example of cyclic silicate.
b) Mg₂SiO₄ is orthosilicate.
c) Basic structural unit in silicates is the SiO₄ tetrahedron.
d) Feldspars are not aluminosilicates.
Answer: d

Question: It is because of inability of ns² electrons of the valence shell to participate in bonding that
a) Sn²⁺ is oxidising while Pb⁴⁺ is reducing
b) Sn²⁺ and Pb²⁺ are both oxidising and reducing
c) Sn⁴⁺ is reducing while Pb⁴⁺ is oxidising
d) Sn²⁺ is reducing while Pb⁴⁺ is oxidising.
Answer: d

Question: The stability of +1 oxidation state among Al, Ga, In and Tl increases in the sequence
a) Al < Ga < In < Tl
b) Tl < In < Ga < Al
c) In < Tl < Ga < Al
d) Ga < In < Al < Tl
Answer: a

Question: The tendency of BF₃, BCl₃ and BBr₃ to behave as Lewis acid decreases in the sequence
a) BCl₃ > BF₃ > BBr₃
b) BBr₃ > BCl₃ > BF₃
c) BBr₃ > BF₃ > BCl₃
d) BF₃ > BCl₃ > BBr₃
Answer: b

Question: Aluminium(III) chloride forms a dimer because aluminium
a) belongs to 3rd group
b) can have higher coordination number
c) cannot form a trimer
d) has high ionization energy.
Answer: b

Question: In graphite, electrons are
a) localised on each C-atom
b) localised on every third C-atom
c) spread out between the structure
d) present in antibonding orbital. 
Answer: c

Question: Aluminium chloride is a/an
a) Bronsted - Lowery acid
b) Arhenius acid
c) Lewis acid
d) Lewis base
Answer: c

Question: Boron forms covalent compound due to
a) higher ionization energy
b) lower ionization energy
c) small size
d) Both higher ionization energy and small size
Answer: d

Question: Ionisation enthalpy (Δ_iH₁kJ mol^–1) for the elements of Group 13 follows the order.
a) B > Al > Ga > In > Tl
b) B < Al < Ga < In < Tl
c) B < Al > Ga < In > Tl
d) B > Al < Ga > In < Tl
Answer: d

Question: Which of the following does not show electrical conduction?
a) Diamond
b) Graphite
c) Potassium
d) Sodium 
Answer: a

Question: The type of hybridisation of boron in diborane is
a) sp^3-hybridisation
b) sp^2-hybridisation
c) sp^-hybridisation
d) sp³d^2-hybridisation.
Answer: a

Question: Which of the following is incorrect statement ?
a) SnF4 is ionic in nature.
b) PbF4 is covalent in nature.
c) SiCl4 is easily hydrolysed.
d) GeX4 (X = F, Cl, Br, I) is more stable than GeX₂.
Answer: b

Question: The straight chain polymer is formed by
a) hydrolysis of CH₃SiCl₃ followed by condensation polymerisation
b) hydrolysis of (CH₃)₄Si by addition polymerisation
c) hydrolysis of (CH₃)₂SiCl₂ followed by condensation polymerisation
d) hydrolysis of (CH₃)₃SiCl followed by condensation polymerisation.
Answer: c

Question: The non-metal oxides are ____x____ whereas metal oxides are ___y ____ in nature.
a) x = acidic or neutral, y = basic
b) x = acidic, y = neutral
c) x = basic, y = acidic
d) x = neutral, y = basic
Answer: a

Question: Which of these is not a monomer for a high molecular mass silicone polymer?
a) Me₃SiCl
b) PhSiCl₃
c) MeSiCl₃
d) Me₂SiCl₂
Answer: a

Question: The exhibition of highest co-ordination number depends on the availability of vacant orbitals in the central atom. Which of the following elements is not likely to act as central atom n 3 MF₆³⁻ ?
a) B
b) Al
c) Ga
d) In
Answer: a

Question: The strongest Lewis acid is
a) BF₃
b) BCl₃
c) BBr₃
d) BI₃
Answer: d

Question: The group 13 element that is liquid during summer and used for measuring high temperature is
a) Boron
b) Aluminium
c) Gallium
d) Indium
Answer: c

Question: AlF₃ is soluble in HF only in presence of KF. It is due to the formation of
a) K₃[AlF₃H₃]
b) K₃[AlF₆]
c) AlH₃
d) K[AlF₃H]
Answer: b

Question: Which of the following compounds is used in cosmetic surgery?
a) Silica
b) Silicates
c) Silicones
d) Zeolites
Answer: c

Question: AlCl₃ on hydrolysis gives
a) Al2O₃. H₂O
b) Al(OH)₃
c) Al₂O₃
d) AlCl3.6H₂O
Answer: b

Question: Which one of the following elements is unable to form MF₆ ^3– ion?
a) Ga
b) Al
c) B
d) In 
Answer: c

Question: Carbon and silicon belong to (IV) group. The maximum coordination number of carbon in commonly occurring compounds is 4, whereas that of silicon is 6. This is due to
a) availability of low lying d-orbitals in silicon
b) large size of silicon
c) more electropositive nature of silicon
d) both large size of silicon and more electropositive nature of silicon.
Answer: a

Question: Which of the following species is not stable?
a) [SiCl₆]^2–
b) [SiF₆]^2–
c) [GeCl₆]^2–
d) [Sn(OH)₆]^2–
Answer: a

Question: Which of the following does not form M3+ ion?
a) Boron
b) Aluminium
c) Indium
d) Gallium
Answer: a

Question: Which one of the following statements about the zeolite is false?
a) They are used as cation exchangers.
b) They have open structure which enables themto take up small molecules.
c) Zeolites are aluminosilicates having three dimensional network.
d) Some of the SiO₄^4– units are replaced by AlO₄^5– and AlO₆ ^9– ions in zeolites. 
Answer: d

Question: The basic structural unit of silicates is
a) SiO₃^2–
b) SiO₄ ^2–
c) SiO^–
d) SiO₄ ^4–
Answer: d

Question: Percentage of lead in lead pencil is
a) 80
b) 20
c) zero
d) 70 
Answer: c

Question: Which of the following oxidation states are the most characteristic for lead and tin respectively?
a) +2, +4
b) +4, +4
c) +2, +2
d) +4, +2 
Answer: a

Question: The relationship between first, second and third ionisation enthalpies of each group-13 element is
a) Δ_iH₁ > Δ_iH₂ > Δ_iH₃
b) Δ_iH₁ < Δ_iH₂ < Δ_iH₃
c) Δ_iH₁ = Δ_iH₂ > Δ_iH₃
d) Δ_iH₃ > Δ_iH₁ > Δ_iH₂
Answer: b

Question: Which of the following properties of aluminium makes it useful for food packaging ?
a) Good electrical conductivity
b) Good thermal conductivity
c) Low density
d) Non toxicity
Answer: c

Question: Which of the following anions is present in the chain structure of silicates?
a) (Si₂O₅^2–)n
b) (SiO₃^2–)n
c) SiO₄  ^4–
d) Si₂O₇ ^6– 
Answer: b

Question: The substance used as a smoke screen in warfare is
a) SiCl₄
b) PH₃
c) PCl₅
d) acetylene
Answer: a

Question: Which out of the following compounds does not exist?
a) BF₃
b) TlCl₃
c) TlCl₅
d) Both TlCl₃ and TlCl₅
Answer: c

Question: Which of the following is/are true regarding gallium?
(i) It has unusually low melting point (303 K).
(ii) It exist in liquid state during summer.
(iii) It has a high boiling point (2676 K).
The correct option is
a) (i) and (ii)
b) (i) and (iii)
c) (i), (ii) and (iii)
d) (ii) and (iii)
Answer: c

Question: Identify the correct statements from the following :
a) CO_2(g) is used as refrigerant for ice-cream and frozen food.
b) The structure of C₆0 contains twelve six carbon rings and twenty five carbon rings.
c) ZSM-5, a type of zeolite, is used to convert alcohols into gasoline.
d) CO is colourless and odourless gas.
a) (a), (b) and (c) only
b) (a) and (c) only
c) (b) and (c) only
d) (c) and (d) only 
Answer: d