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Explore popular questions from Some pBlock Elements for NEET. This collection covers Some pBlock Elements previous year NEET questions hand picked by experienced teachers.

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Q 1. It is because of inability of {tex} \mathrm{n s} ^ { 2 } {/tex} electrons of the valence shell to participate in bonding that

A

{tex} \mathrm { Sn } ^ { 2 + } {/tex} is oxidising while {tex} \mathrm { Pb } ^ { 4 + } {/tex} is reducing

B

{tex} \mathrm { Sn } ^ { 2 + } {/tex} and {tex} \mathrm { Pb } ^ { 2 + } {/tex} are both oxidising and reducing

C

{tex} \mathrm { Sn } ^ { 4 + } {/tex} is reducing while {tex} \mathrm { Pb } ^ { 4 + } {/tex} is oxidising

{tex} \mathrm { Sn } ^ { 2 + } {/tex} is reducing while {tex} \mathrm { Pb } ^ { 4 + } {/tex} is oxidising.

Explanation


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Q 2. Boric acid is an acid because its molecule

A

contains replaceable {tex} \mathrm { H } ^ { + } {/tex} ion

B

gives up a proton

accepts {tex}\mathrm {OH^{-}}{/tex} from water releasing proton

D

combines with proton from water molecule.

Explanation



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Q 3. {tex}\mathrm{AlF_{3}}{/tex} is soluble in {tex}\mathrm{HF}{/tex} only in presence of {tex}\mathrm{KF}{/tex}. It is due to the formation of

A

{tex} \mathrm { K } _ { 3 } \left[ \mathrm { AlF } _ { 3 } \mathrm { H } _ { 3 } \right] {/tex}

{tex} \mathrm { K } _ { 3 } \left[ \mathrm { AlF } _ { 6 } \right] {/tex}

C

{tex} \mathrm { AlH_{3} } {/tex}

D

{tex} \mathrm { K } \left[ \mathrm { AlF } _ { 3 } \mathrm { H } \right] {/tex}

Explanation


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Q 4. The stability of {tex} + 1 {/tex} oxidation state among {tex}\mathrm {Al, Ga, In}{/tex} and {tex}\mathrm{TI}{/tex} increases in the sequence

{tex} \mathrm { Al } < \mathrm { Ga } < \mathrm { In } < \mathrm { TI } {/tex}

B

{tex} \mathrm { TI } < \mathrm { In } < \mathrm { Ga } < \mathrm { Al } {/tex}

C

{tex} \mathrm { In } < \mathrm { TI } < \mathrm { Ga } < \mathrm { Al } {/tex}

D

{tex} \mathrm { Ga } < \mathrm { In } < \mathrm { Al } < \mathrm { TI } {/tex}

Explanation


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Q 5. Which of the following structure is similar to graphite?

A

{tex} \mathrm { B } _ { 4 } \mathrm { C } {/tex}

B

{tex} \mathrm { B } _ { 2 } \mathrm { H } _ { 6 } {/tex}

{tex} \mathrm { BN } {/tex}

D

{tex} \mathrm { B } {/tex}

Explanation


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Q 6. Which of these is not a monomer for a high molecular mass silicone polymer?

{tex} \mathrm { Me } _ { 3 } \mathrm { SiCl } {/tex}

B

{tex}\mathrm { PhSiCl_{3}}{/tex}

C

{tex} \mathrm { MeSiCl } _ { 3 } {/tex}

D

{tex} \mathrm { Me } _ { 2 } \mathrm { SiCl } _ { 2 } {/tex}

Explanation


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Q 7. The basic structural unit of silicates is

A

{tex} \mathrm { SiO } _ { 3 } ^ { 2- } {/tex}

B

{tex} \mathrm { SiO } _ { 4 } ^ { 2-} {/tex}

C

{tex}\mathrm {SiO^{-}}{/tex}

{tex} \mathrm { SiO } _ { 4 } ^ { 4- } {/tex}

Explanation

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Q 8. Which statement is wrong?

A

Beryl is an example of cyclic silicate.

B

{tex} \mathrm { Mg } _ { 2 } \mathrm { SiO } _ { 4 } {/tex} is orthosilicate.

C

Basic structural unit in silicates is the {tex}\mathrm{SiO_ 4}{/tex} tetrahedron.

Feldspars are not aluminosilicates.

Explanation


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Q 9. Name the two type of the structure of silicate in which one oxygen atom of {tex} \left[ \mathrm { SiO } _ { 4 } \right] ^ { 4- } {/tex} is shared?

A

Linear chain silicate

B

Sheet silicate

Pyrosilicate

D

Three dimensional

Explanation


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Q 10. Which of the following statements is incorrect?

A

Pure sodium metal dissolves in liquid ammonia to give blue solution.

B

{tex} \mathrm { NaOH } {/tex} reacts with glass to give sodium silicate.

Aluminium reacts with excess {tex} \mathrm { NaOH } {/tex} to give {tex} \mathrm { Al } ( \mathrm { OH } ) _ { 3 } {/tex}

D

{tex} \mathrm { NaHCO } _ { 3 } {/tex} on heating gives {tex} \mathrm { Na } _ { 2 } \mathrm { CO } _ { 3 } {/tex}

Explanation


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Q 11. Which of the following oxide is amphoteric?

{tex} \mathrm { SnO } _ { 2 } {/tex}

B

{tex} \mathrm { CaO } {/tex}

C

{tex} \mathrm { SiO } _ { 2 } {/tex}

D

{tex} \mathrm { CO } _ { 2 } {/tex}

Explanation


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Q 12. Which one of the following molecular hydrides acts as a Lewis acid?

A

{tex} \mathrm { NH } _ { 3 } {/tex}

B

{tex} \mathrm { H } _ { 2 } \mathrm { O } {/tex}

{tex} \mathrm { B } _ { 2 } \mathrm { H } _ { 6 } {/tex}

D

{tex} \mathrm { CH } _ { 4 } {/tex}

Explanation


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Q 13. The tendency of {tex} \mathrm { BF } _ { 3 } , \mathrm { BCl } _ { 3 } {/tex} and {tex} \mathrm { BBr } _ { 3 } {/tex} to behave as Lewis acid decreases in the sequence

A

{tex} \mathrm { BCl } _ { 3 } > \mathrm { BF } _ { 3 } > \mathrm { BBr } _ { 3 } {/tex}

{tex} \mathrm { BBr } _ { 3 } > \mathrm { BCl } _ { 3 } > \mathrm { BF } _ { 3 } {/tex}

C

{tex} \mathrm { BBr } _ { 3 } > \mathrm { BF } _ { 3 } > \mathrm { BCl } _ { 3 } {/tex}

D

{tex} \mathrm { BF } _ { 3 } > \mathrm { BCl } _ { 3 } > \mathrm { BBr } _ { 3 } {/tex}

Explanation

A molecule is said to be a lewis acid if it can accept a lone pair. When the halide is more electronegative the interelectronic repulsion increases making the molecule difficult to accept a lone pair. Size of halide also behaves in the same way. Also the degree of hydrolysis increases from fluorine to iodine,so the lewis acidic character increases in the same order. So,the order of lewis acidity is

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Q 14. The straight chain polymer is formed by

A

hydrolysis of {tex} \mathrm { CH } _ { 3 } \mathrm { SiCl } _ { 3 } {/tex} followed by condensation polymerisation

B

hydrolysis of {tex} \left( \mathrm { CH } _ { 3 } \right) _ { 4 } \mathrm { Si } {/tex} by addition polymerisation

hydrolysis of {tex} \left( \mathrm { CH } _ { 3 } \right) _ { 2 } \mathrm { SiCl } _ { 2 } {/tex} followed by condensation polymerisation

D

hydrolysis of {tex} \left( \mathrm { CH } _ { 3 } \right) _ { 3 } \mathrm { SiCl } {/tex} followed by condensation polymerisation.

Explanation


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Q 15. Which of the following oxidation states are the most characteristic for lead and tin respectively?

{tex} + 2, + 4 {/tex}

B

{tex} + 4 , + 4 {/tex}

C

{tex} + 2 , + 2 {/tex}

D

{tex} + 4 , + 2 {/tex}

Explanation


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Q 16. Which of the following anions is present in the chain structure of silicates?

A

{tex} \left( \mathrm { Si } _ { 2 } \mathrm { O } _ { 5 } ^ { 2- } \right)_{n} {/tex}

{tex} \left( \mathrm { SiO } _ { 3 } ^ { 2 } \right) _ { n } {/tex}

C

{tex} \mathrm { Si } \mathrm { O } _ { 4 } ^ { 4- } {/tex}

D

{tex} \mathrm { Si } _ { 2 } \mathrm { O } _ { 7 } ^ { 6- } {/tex}

Explanation


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Q 17. Which of the following is the most basic oxide?

A

{tex} \mathrm { SeO } _ { 2 } {/tex}

B

{tex} \mathrm { Al } _ { 2 } \mathrm { O } _ { 3 } {/tex}

C

{tex} \mathrm { Sb } _ { 2 } \mathrm { O } _ { 3 } {/tex}

{tex} \mathrm { Bi } _ { 2 } \mathrm { O } _ { 3 } {/tex}

Explanation


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Q 18. 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 them to take up small molecules.

C

Zeolites are aluminosilicates having three dimensional network.

Some of the {tex} \mathrm { SiO } _ { 4 } ^ { 4 - } {/tex} units are replaced by {tex} \mathrm { AlO } _ { 4 } ^ { 5 - } {/tex} and {tex} \mathrm { AlO } _ { 6 } ^ { 9- } {/tex} ions in zeolites.

Explanation


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Q 19. Which one of the following compounds is not a protonic acid?

{tex} \mathrm { B } ( \mathrm { OH } ) _ { 3 } {/tex}

B

{tex} \mathrm { PO } ( \mathrm { OH } ) _ { 3 } {/tex}

C

{tex} \mathrm { SO } ( \mathrm { OH } )_{2} {/tex}

D

{tex} \mathrm { SO } _ { 2 } ( \mathrm { OH } ) _ { 2 } {/tex}

Explanation


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Q 20. Which compound is electron deficient?

A

{tex} \mathrm { BeCl } _ { 2 } {/tex}

{tex} \mathrm { BCl _ { 3 }} {/tex}

C

{tex} \mathrm { CCl } _ { 4 } {/tex}

D

{tex} \mathrm { PCl } _ { 5 } {/tex}

Explanation


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Q 21. Which of the following does not show electrical conduction?

Diamond

B

Graphite

C

Potassium

D

Sodium

Explanation


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Q 22. The type of hybridisation of boron in diborane is

{tex} s p ^ { 3 } {/tex} -hybridisation

B

{tex} s p ^ { 2 } {/tex} -hybridisation

C

{tex}sp{/tex}-hybridisation

D

{tex} s p ^ { 3 } d ^ { 2 } - {/tex} hybridisation

Explanation


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Q 23. Percentage of lead in lead pencil is

A

80

B

20

Zero

D

70

Explanation


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Q 24. In graphite, electrons are

A

localised on each C-atom

B

localised on every third C-atom

spread out between the structure

D

present in anti-bonding orbital.