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Explore popular questions from d and f Block Elements for NEET. This collection covers d and f Block Elements previous year NEET questions hand picked by popular teachers.


Q 1.    

Correct4

Incorrect-1

Name the gas that can readily decolourise acidified {tex}\mathrm{KMnO_{4}}{/tex} solution.

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

B

{tex} \mathrm { NO } _ { 2 } {/tex}

C

{tex} \mathrm { P } _ { 2 } \mathrm { O } _ { 5 } {/tex}

D

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

Explanation


Q 2.    

Correct4

Incorrect-1

{tex}\mathrm{HgCl_{2}}{/tex} and {tex}\mathrm{I_{2}}{/tex} both when dissolved in water containing {tex}\mathrm{I^{-}}{/tex} ions, the pair of species formed is

A

{tex} \mathrm { HgI } _ { 2 } , \mathrm { I } ^ { - } {/tex}

{tex} \mathrm { HgI } _ { 4 } ^ { 2 - } , \mathrm { I } _ { 3 } ^ { - } {/tex}

C

{tex} \mathrm { Hg } _ { 2 } \mathrm { I } _ { 2 } , \mathrm { I } ^ { - } {/tex}

D

{tex} \mathrm { HgI } _ { 2 } , \mathrm { I } _ { 3 } ^ { - } {/tex}

Explanation

Q 3.    

Correct4

Incorrect-1

The reason for greater range of oxidation states in actinoids is attributed to

A

actinoid contraction

{tex}5f, 6d {/tex} and {tex} 7s {/tex} levels having comparable energies

C

{tex} 4f {/tex} and {tex} 5d {/tex} levels being close in energies

D

the radioactive nature of actinoids.

Explanation


Q 4.    

Correct4

Incorrect-1

Which one of the following statements related to lanthanons is incorrect?

A

Europium shows {tex} + 2 {/tex} oxidation state.

B

The basicity decreases as the ionic radius decreases from Pr to Lu.

All the lanthanons are much more reactive than aluminium.

D

Ce {tex} ( + 4 ) {/tex} solutions are widely used as oxidizing agent in volumetric analysis.

Explanation


Q 5.    

Correct4

Incorrect-1

Which one of the following statements is correct when {tex} \mathrm { SO } _ { 2 } {/tex} is passed through acidified {tex} \mathrm { K } _ { 2 } \mathrm { Cr } _ { 2 } \mathrm { O } _ { 7 } {/tex} solution?

A

{tex} \mathrm { SO } _ { 2 } {/tex} is reduced

Green {tex} \mathrm { Cr } _ { 2 } \left( \mathrm { SO } _ { 4 } \right) _ { 3 } {/tex} is formed.

C

The solution turns blue.

D

The solution is decolourised.

Explanation

Q 6.    

Correct4

Incorrect-1

The electronic configurations of Eu (Atomic No. 63 ) , Gd (Atomic No. 64 ) and Tb (Atomic No. 65 ) are

A

{tex} [ \mathrm { Xe } ] 4 f ^ { 6 } 5 d ^ { 1 }6 s ^ { 2 } , [ \mathrm { Xe } ] 4 f ^ { 7 } 5 d ^ { 1 } 6 s ^ { 2 } {/tex} and {tex} [ \mathrm { Xe } ] 4 f ^ { 8 }5 d ^ { 1 } 6 s ^ { 2 } {/tex}

{tex} [ \mathrm { Xe } ] 4 f ^ { 7 } 6 s ^ { 2 } , [ \mathrm { Xe } ] 4 f ^ { 7 } 5 d ^ { 1 } 6 s ^ { 2 } {/tex} and {tex} [ \mathrm { Xe } ] 4 f ^ { 9 } 6 s ^ { 2 } {/tex}

C

{tex} [ \mathrm { Xe } ] 4 f ^ { 7 } 6 s ^ { 2 } , [ \mathrm { Xe } ] 4 f ^ { 8 } 6 s ^ { 2 } {/tex} and {tex} [ \mathrm { Xe } ] 4 f ^ { 8 } 5 d ^ { 1 } 6 s ^ { 2 } {/tex}

D

{tex} [ \mathrm { Xe } ] 4 f ^ { 6 } 5 d ^ { 1 } 6 s ^ { 2 } , [ \mathrm { Xe } ] 4 f ^ { 7 }5 d ^ { 1 } 6 s ^ { 2 } {/tex} and {tex} [ \mathrm { Xe } ] 4 f ^ { 9 } 6 s ^ { 2 } {/tex}

Explanation

Q 7.    

Correct4

Incorrect-1

Gadolinium belongs to 4{tex} f {/tex} series. Its atomic number is {tex} 64 . {/tex} Which of the following is the correct electronic configuration of gadolinium?

A

{tex} [ \mathrm { Xe } ] 4 f ^ { 9 } 5 s ^ { 1 } {/tex}

{tex} [ \mathrm { Xe } ] 4 f ^ { 7 } 5 d ^ { 1 } 6 s ^ { 2 } {/tex}

C

{tex} [ \mathrm { Xe } ] 4 f ^ { 6 } 5 d ^ { - 6 } 6 s ^ { 2 } {/tex}

D

{tex} [ \mathrm { Xe } ] 4 f ^ { 8 } 6 d ^ { 2 } {/tex}

Explanation

Q 8.    

Correct4

Incorrect-1

Assuming complete ionisation, same moles of which of the following compounds will require the least amount of acidified {tex} \mathrm { KMnO } _ { 4 } {/tex} for complete oxidation?

A

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

B

{tex} \mathrm { FeC } _ { 2 } \mathrm { O } _ { 4 } {/tex}

C

{tex} \mathrm { Fe } \left( \mathrm { NO } _ { 2 } \right) _ { 2 } {/tex}

{tex} \mathrm { FeSO_{4} } {/tex}

Explanation



Q 9.    

Correct4

Incorrect-1

Magnetic moment {tex} \mathrm {2.84 \ B. } \mathrm { M. } {/tex} is given by {tex} \text { (At. nos. } \mathrm { Ni } = 28 , \mathrm { Ti } = 22 , \mathrm { Cr } = 24 , \mathrm { Co } = 27 ) {/tex}

A

{tex} \mathrm { Cr } ^ { 2 + } {/tex}

B

{tex} \mathrm { Co }^ { 2 + } {/tex}

{tex} \mathrm { Ni } ^ { 2 + } {/tex}

D

{tex} \mathrm { Ti } ^ { 3+ } {/tex}

Explanation


Q 10.    

Correct4

Incorrect-1

Which of the following processes does not involve oxidation of iron?

Formation of {tex} \mathrm { Fe } ( \mathrm { CO } ) _ { \mathrm { s } } {/tex} from {tex} \mathrm { Fe } {/tex}

B

Liberation of {tex} \mathrm { H } _ { 2 } {/tex} from steam by iron at high temperature.

C

Rusting of iron sheets.

D

Decolourisation of blue {tex} \mathrm { CuSO } _ { 4 } {/tex} solution by iron.

Explanation

Q 11.    

Correct4

Incorrect-1

Because of lanthanoid contraction, which of the following pairs of elements have nearly of same atomic radii? (Numbers in the parenthesis are atomic numbers)

{tex} \mathrm { Zr } ( 40 ) {/tex} and {tex} \mathrm { Hf } ( 72 ) {/tex}

B

{tex} \mathrm { Zr } ( 40 ) {/tex} and {tex} \mathrm { Ta } ( 73 ) {/tex}

C

{tex} \operatorname { Ti } ( 22 ) {/tex} and {tex} \mathrm { Z r }( 40 ) {/tex}

D

{tex} \mathrm { Zr } ( 40 ) {/tex} and {tex} \mathrm { Nb } ( 41 ) {/tex}

Explanation


Q 12.    

Correct4

Incorrect-1

The reaction of aqueous {tex} \mathrm { KMnO } _ { 4 } {/tex} with {tex} \mathrm { H } _ { 2 } \mathrm { O } _ { 2 } {/tex} in acidic conditions gives

A

{tex} \mathrm { Mn } ^ { 4 + } {/tex} and {tex} \mathrm { O } _ { 2 } {/tex}

{tex} \mathrm { Mn } ^ { 2 + } {/tex} and {tex} \mathrm { O } _ { 2 } {/tex}

C

{tex} \mathrm { Mn } ^ { 2 + } {/tex} and {tex} \mathrm { O } _ { 3 } {/tex}

D

{tex} \mathrm { Mn } ^ { 4 + }{/tex}and {tex} \mathrm { MnO } _ { 2 } {/tex}

Explanation


Q 13.    

Correct4

Incorrect-1

Magnetic moment {tex} \mathrm { 2.83\ B.M. } {/tex} is given by which of the following ions? (At. nos. {tex}\mathrm {Ti} = 22 , \mathrm { Cr } = 24 , \mathrm { Mn } = 25 , \mathrm { Ni } = 28 {/tex} )

A

{tex} \mathrm { Ti } ^ { 3+ } {/tex}

{tex} \mathrm { Ni } ^ { 2+ } {/tex}

C

{tex} \mathrm { Cr } ^ { 3+ } {/tex}

D

{tex} \mathrm { Mn } ^ { 2 + } {/tex}

Explanation


Q 14.    

Correct4

Incorrect-1

Reason of lanthanoid contraction is

negligible screening effect of {tex} 'f'{/tex} -orbitals

B

increasing nuclear charge

C

decreasing nuclear charge

D

decreasing screening effect.

Explanation


Q 15.    

Correct4

Incorrect-1

Which of the following statements about the interstitial compounds is incorrect?

A

They are much harder than the pure metal.

B

They have higher melting points than the pure metal.

C

They retain metallic conductivity.

They are chemically reactive.

Explanation


Q 16.    

Correct4

Incorrect-1

Which of the following lanthanoid ions is diamagnetic? (At. nos.{tex}\ \mathrm {Ce} = 58 , \mathrm { Sm } = 62 , \mathrm { Eu } = 63 , \mathrm { Yb } = 70 {/tex} )

A

{tex} \mathrm { Eu } ^ { 2+ } {/tex}

{tex} \mathrm { Yb } ^ { 2+ } {/tex}

C

{tex} \mathrm { Ce } ^ { 2+ } {/tex}

D

{tex} \mathrm { Sm } ^ { 2+ } {/tex}

Explanation


Q 17.    

Correct4

Incorrect-1

Identify the correct order of solubility in aqueous medium.

A

{tex} \mathrm { Na } _ { 2 } \mathrm { S } > \mathrm { CuS } > \mathrm { ZnS } {/tex}

{tex} \mathrm { Na } _ { 2 } \mathrm { S } > \mathrm { ZnS } > \mathrm { CuS } {/tex}

C

{tex} \mathrm { CuS } > \mathrm { ZnS } > \mathrm { Na } _ { 2 } \mathrm { S } {/tex}

D

{tex} \mathrm { ZnS } > \mathrm { Na } _ { 2 } \mathrm { S } > \mathrm { CuS } {/tex}

Explanation


Q 18.    

Correct4

Incorrect-1

{tex}\mathrm{Sc ( Z = 21 )} {/tex} is a transition element but {tex}\mathrm{ Z n }{/tex} {tex}\mathrm{ ( Z = 30 ) }{/tex} is not because

A

both {tex} \mathrm { Sc } ^ { 3 + } {/tex} and {tex} \mathrm { Zn } ^ { 2 + } {/tex} ions are colourless and form white compounds.

in case of {tex} \mathrm { Sc } , 3 d {/tex} orbitals are partially filled but in {tex} \mathrm { Zn } {/tex} these are filled.

C

last electron is assumed to be added to 4{tex} s {/tex} level in case of {tex} \mathrm { Zn. } {/tex}

D

both {tex} \mathrm {Sc}{/tex} and {tex} \mathrm {Zn}{/tex} do not exhibit variable oxidation states.

Explanation


Q 19.    

Correct4

Incorrect-1

Identify the alloy containing a non-metal as a constituent in it.

A

Invar

Steel

C

Bell metal

D

Bronze

Explanation

Q 20.    

Correct4

Incorrect-1

Which of the statements is not true?

A

On passing {tex} \mathrm { H } _ { 2 } \mathrm { S } {/tex} through acidified {tex} \mathrm { K } _ { 2 } \mathrm { Cr } _ { 2 } \mathrm { O } _ { 7 } {/tex} solution, a milky colour is observed.

{tex} \mathrm { Na } _ { 2 } \mathrm { Cr } _ { 2 } \mathrm { O } _ { 7 } {/tex} is preferred over {tex} \mathrm { K } _ { 2 } \mathrm { Cr } _ { 2 } \mathrm { O } _ { 7 } {/tex} in volumetric analysis.

C

{tex} \mathrm { K } _ { 2 } \mathrm { Cr } _ { 2 } \mathrm { O } _ { 7 } {/tex} solution in acidic medium is orange.

D

{tex} \mathrm { K } _ { 2 } \mathrm { Cr } _ { 2 } \mathrm { O } _ { 7 } {/tex} solution becomes yellow on increasing the pH beyond {tex} 7 . {/tex}

Explanation

Q 21.    

Correct4

Incorrect-1

The catalytic activity of transition metals and their compounds is ascribed mainly to

A

their magnetic behaviour

B

their unfilled {tex} d {/tex} -orbitals

their ability to adopt variable oxidation states

D

their chemical reactivity

Explanation

Q 22.    

Correct4

Incorrect-1

Which of the following exhibits only {tex} + 3 {/tex} oxidation state?

A

U

B

{tex} \mathrm { Th } {/tex}

{tex} \mathrm { Ac }{/tex}

D

{tex} \mathrm { Pa} {/tex}

Explanation


Q 23.    

Correct4

Incorrect-1

Which one of the following does not correctly represent the correct order of the property indicated against it?

A

{tex} \mathrm { Ti < V < C r < M n }; {/tex} increasing number of oxidation states

B

{tex} \mathrm { Ti } ^ { 3 + } < \mathrm { V } ^ { 3 + } < \mathrm { Cr } ^ { 3 + } < \mathrm { Mn } ^ { 3 + } {/tex} : increasing magnetic moment

{tex} \mathrm { Ti } < \mathrm { V } < \mathrm { Cr } < \mathrm { Mn } : {/tex} increasing melting points

D

{tex} \mathrm { Ti } < \mathrm { V } < \mathrm { Mn } < \mathrm { Cr } : {/tex} increasing {tex} 2 ^ { \text {nd } } {/tex} ionization enthalpy

Explanation



Q 24.    

Correct4

Incorrect-1

Four successive members of the first series of the transition metals are listed below. For which one of them the standard potential {tex} \left( E _ { M^{2+}/M } ^ { o} \right) {/tex} value has a positive sign?

A

{tex} \operatorname { Co } ( Z = 27 ) {/tex}

B

Ni {tex} ( Z = 28 ) {/tex}

Cu {tex} ( Z = 29 ) {/tex}

D

Fe {tex} ( Z = 26 ) {/tex}

Explanation


Q 25.    

Correct4

Incorrect-1

For the four successive transition elements {tex} ( \mathrm { Cr } , \mathrm { Mn } , \mathrm { Fe } \text { and } \mathrm { Co } ) , {/tex} the stability of {tex} + 2 {/tex} oxidation state will be there in which of the following order?
(At. nos. {tex} \mathrm { Cr } = 24 , \mathrm { Mn } = 25 , \mathrm { Fe } = 26 , \mathrm { Co } = 27 {/tex}

{tex} \mathrm { Mn } > \mathrm { Fe } > \mathrm { Cr } > \mathrm { Co } {/tex}

B

{tex} \mathrm { Fe } > \mathrm { Mn } > \mathrm { Co } > \mathrm { Cr } {/tex}

C

{tex} \mathrm { Co } > \mathrm { Mn } > \mathrm { Fe } > \mathrm { Cr } {/tex}

D

{tex} \mathrm { Cr } > \mathrm { Mn } > \mathrm { Co } > \mathrm { Fe } {/tex}

Explanation