How many questions from d- and f-Block Elements appear in JEE?

d- and f-Block Elements has appeared in 126 of the last 186 JEE Main and JEE Advanced papers — about 68% of them — contributing 202 questions in total across those papers.

Is d- and f-Block Elements an important chapter for JEE?

Judged by how often it is actually tested, it appears in roughly 68% of papers. Chapters above about 50% are effectively guaranteed to show up every session, so they repay thorough preparation; lower-frequency chapters are better treated as targeted revision.

Where do these d- and f-Block Elements questions come from?

Every question is from an official JEE Main or JEE Advanced paper, transcribed from the original paper and tagged to this chapter. Answers follow the official answer key.

d- and f-Block Elements JEE Previous Year Questions with Answers

Q1·ChemistrySingle correctJEE Main 2026

Given below are two statements for catalytic properties of transition metals. Statement I: First row transition metals which act as catalyst utilise their 3d electrons only for formation of bonds between reactant molecules and atoms on the surface of catalyst. Statement II: There is increase in the concentration of reactants on the surface of catalyst which strengthens the bonds in reacting molecules. In the light of the above statements, choose the correct answer from the options given below:

(A)Both Statement I and Statement II are correct
(B)Both Statement I and Statement II are incorrect
(C)Statement I is correct but Statement II is incorrect
(D)Statement I is incorrect but Statement II is correct

Q2·ChemistrySingle correctJEE Main 2026

Given below are two statements: Statement I: The number of pairs among

[Ti^{4+}, V^{2+}]

,

[V^{2+}, Mn^{2+}]

,

[Mn^{2+}, Fe^{3+}]

and

[V^{2+}, Cr^{2+}]

in which both ions are coloured is 3. Statement II: The number of pairs among

[La^{3+}, Yb^{2+}]

,

[Lu^{3+}, Ce^{4+}]

and

[Ac^{3+}, Lr^{3+}]

ions in which both are diamagnetic is 3. In the light of the above statements, choose the correct from the options given below:

(A)Both Statement I and Statement II are correct
(B)Both Statement I and Statement II are incorrect
(C)Statement I is correct but Statement II is incorrect
(D)Statement I is incorrect but Statement II is correct

Q3·ChemistrySingle correctJEE Main 2026

The correct order of first

(\Delta_{i}H_{1})

and second

(\Delta_{i}H_{2})

ionisation enthalpy values of Cr and Mn are : A.

\Delta_{i}H_{1}

: Cr > Mn B.

\Delta_{i}H_{2}

: Cr > Mn C.

\Delta_{i}H_{1}

: Mn > Cr D.

\Delta_{i}H_{2}

: Mn > Cr Choose the correct answer from the options given below :

(A)A and B only
(B)B and C only
(C)A and D only
(D)C and D only

Q4·ChemistrySingle correctJEE Main 2026

The correct statements among the following are. A. Basic vanadium oxide is used in the manufacture of H₂SO₄. B. The spin-only magnetic moment value of the transition metal halide employed in Ziegler-Natta polymerization is 2.84 BM. C. The p-block metal compound employed in Ziegler-Natta polymerization has the metal in +3 oxidation state. D. The number of electrons present in the outer most 'd' orbital of metal halide employed in Wacker process is 8. Choose the correct answer from the options given below:

(A)A and B Only
(B)A, C and D Only
(C)C and D Only
(D)B, C and D Only

Q5·ChemistrySingle correctJEE Main 2026

Which of the following is NOT a physical or chemical characteristics of interstitial compounds?

(A)They have high melting points, higher than those of pure metals.
(B)They are very soft and ionic in nature.
(C)They retain metallic conductivity.
(D)They are chemically inert and usually non-stoichiometric.

Q6·ChemistrySingle correctJEE Main 2026

The correct statements among the following are, A.

Mo(VI)

and

W(VI)

are less stable than

Cr(VI)

. B.

Ce^{4+}

and

Tb^{4+}

are oxidant while

Eu^{2+}

and

Yb^{2+}

are reductant. C.

Cm

and

Am

have seven unpaired electrons. D. Actinoid contraction is greater from element to element than lanthanoid contraction. Choose the correct answer from the options given below:

(A)A and B Only
(B)C and D Only
(C)B and D Only
(D)A and C Only

Q7·ChemistrySingle correctJEE Main 2026

Consider

|x|

is the difference in oxidation states of Mn in highest manganese fluoride and highest manganese oxide. The ions with

|x|

number of unpaired electrons from the following are: A.

Sc^{3+}

B.

Zn^{2+}

C.

V^{2+}

D.

Fe^{2+}

E.

Co^{2+}

Choose the correct answer from the options given below:

(A)A and B Only
(B)C, D and E Only
(C)C and E Only
(D)B and E Only

Q8·ChemistrySingle correctJEE Main 2026

Correct statements from the following are A. Potassium dichromate is an oxidising agent and it oxidises

FeSO_4

to

Fe_2(SO_4)_3

in acidic medium. B. Sodium dichromate can be used as primary standard in volumetric estimation. C.

CrO_4^{2-}

and

Cr_2O_7^{2-}

are interconvertible in aqueous solution by varying the

pH

of the solution. D.

Cr\text{-}O\text{-}Cr

bond angle in

Cr_2O_7^{2-}

is

126^{\circ}

. Choose the correct answer from the options given below:

(A)A, B and C Only
(B)A, C and D Only
(C)A and C Only
(D)B and D Only

Q9·ChemistrySingle correctJEE Main 2026

Pairs of elements with the same number of electrons in their respective 4f orbital are [Atomic number. Eu-63, Gd-64, Dy-66, Ho-67, Tm-69, Yb-70, Lu-71, Hf-72] A. (Eu and Gd) B. (Dy and Ho) C. (Yb and Hf) D. (Lu and Tm) Choose the correct answer from the options given below:

(A)B and C Only
(B)A and B Only
(C)A and D Only
(D)A and C Only

Q10·ChemistrySingle correctJEE Main 2026

Given below are two statements: Statement I: Among

Zn

,

Mn

,

Sc

and

Cu

, the energy required to remove the third valence electron is highest for

Zn

and lowest for

Sc

. Statement II: The correct order of the following complexes in terms of CFSE is

[Co(H_2O)_6]^{2+} < [Co(H_2O)_6]^{3+} < [Co(en)_3]^{3+}

. In the light of the above statements, choose the correct answer from the options given below:

(A)Both Statement I and Statement II are true
(B)Both Statement I and Statement II are false
(C)Statement I is true but Statement II is false
(D)Statement I is false but Statement II is true

Q11·ChemistrySingle correctJEE Main 2026

Among

Fe^{2+}, Fe^{3+}, Cr^{2+}

and

Zn^{2+}

, the ion that shows positive borax bead test and with highest ionisation enthalpy is:

(A) $Fe^{2+}$
(B) $Zn^{2+}$
(C) $Cr^{2+}$
(D) $Fe^{3+}$

Q12·ChemistryNumericalJEE Main 2026

Number of paramagnetic ions among the following d- and f-block metal ions is ________.

Mn^{2+}, Cu^{2+}, Zn^{2+}, Yb^{2+}, Sc^{3+}, La^{3+}, Gd^{3+}, Lu^{3+}, Ti^{4+}, Ce^{4+}

(Atomic number of

Mn = 25, Cu = 29, Zn = 30, Yb = 70, Sc = 21, La = 57, Gd = 64, Lu = 71, Ti = 22, Ce = 58

)

Q13·ChemistrySingle correctJEE Main 2026

Which of the following sets includes all the species that will change the orange colour of

\mathrm{K_{2}Cr_{2}O_{7}}

in acidic medium?

(A) $\mathrm{Fe^{2+}}, \mathrm{Sn^{2+}}, \mathrm{I^{-}}, \mathrm{S^{2-}}$
(B) $\mathrm{S^{2-}}, \mathrm{Fe^{3+}}, \mathrm{I^{-}}, \mathrm{C_{2}O_{4}^{2-}}$
(C) $\mathrm{Fe^{2+}}, \mathrm{NO_{2}^{-}}, \mathrm{SO_{2}}, \mathrm{Sn^{4+}}$
(D) $\mathrm{Fe^{3+}}, \mathrm{SO_{4}^{2-}}, \mathrm{S^{2-}}, \mathrm{Sn^{4+}}$

Q14·ChemistrySingle correctJEE Main 2026

Given below are two statements : Statement I : The number of pairs, from the following, in which both the ions are coloured in aqueous solution is 3. [Sc

^{3+}

, Ti

^{3+}

], [Mn

^{2+}

, Cr

^{2+}

], [Cu

^{2+}

, Zn

^{2+}

] and [Ni

^{2+}

, Ti

^{4+}

] Statement II : Th

^{4+}

is the strongest reducing agent among Th

^{4+}

, Ce

^{4+}

, Gd

^{3+}

and Eu

^{2+}

. In the light of the above statements, choose the correct answer from the options given below

(A)Statement I is true but Statement II is false
(B)Statement I is false but Statement II is true
(C)Both Statement I and Statement II are false
(D)Both Statement I and Statement II are true

Q15·ChemistrySingle correctJEE Main 2026

Consider the following statements about manganate and permanganate ions. Identify the correct statements : A. The geometry of both manganate and permanganate ions is tetrahedral. B. The oxidation states of Mn in manganate and permanganate are +7 and +6, respectively. C. Oxidation of Mn(II) salt by peroxodisulphate gives manganate ion as the final product. D. Manganate ion is paramagnetic and permanganate ions is diamagnetic. E. Acidified permanganate ion reduces oxalate, nitrite and iodide ions. Choose the correct answer from the options given below:

(A)A, C and D Only
(B)A, B and C Only
(C)A, D and E Only
(D)A and D Only

Q16·ChemistrySingle correctJEE Main 2026

"X" is an oxoanion of the lightest element of group 7 (in the periodic table). The metal is in +6 oxidation state in "X". The color of the potassium salt of X is

(A)green
(B)purple
(C)yellow
(D)orange

Q17·ChemistrySingle correctJEE Main 2026

Given below are two statements : Statement-I L: The first ionization enthalpy of Cr is lower than that of Mn. Statement-II : The second and third ionization enthalpies of Cr are higher than those of Mn. In the light of the above statements, choose the correct answer from the options given below :

(A)Both Statement-I and Statement-II are false.
(B)Statement-I is true but Statement-II is false.
(C)Both Statement-I and Statement-II are true.
(D)Statement-I is false but Statement-II is true.

Q18·ChemistryNumericalJEE Main 2026

Among the following oxides of 3d elements, the number of mixed oxides are_________.

Ti_{2}O_{3}

,

V_{2}O_{4}

,

Cr_{2}O_{3}

,

Mn_{3}O_{4}

,

Fe_{3}O_{4}

,

Fe_{2}O_{3}

,

Co_{3}O_{4}

Q19·ChemistrySingle correctJEE Main 2026

On heating a mixture of common salt and

\text{K}_{2}\text{Cr}_{2}\text{O}_{7}

in equal amount along with concentrated

\text{H}_{2}\text{SO}_{4}

in a test tube, a gas is evolved. Formula of the gas evolved and oxidation state of the central metal atom in the gas respectively are :

(A) $\text{CrO}_{2}\text{Cl}_{2}$ and $+5$
(B) $\text{CrO}_{2}\text{Cl}_{2}$ and $+6$
(C) $\text{Cr}_{2}\text{O}_{2}\text{Cl}_{2}$ and $+6$
(D) $\text{Cr}_{2}\text{O}_{2}\text{Cl}_{2}$ and $+3$

Q20·ChemistrySingle correctJEE Main 2026

MnO_4^{2-}

, in acidic medium, disproportionates to :

(A) $Mn_2O_7$ and $MnO_2$
(B) $MnO_4^-$ and MnO
(C) $MnO_4^-$ and $MnO_2$
(D) $Mn_2O_7$ and MnO

Q21·ChemistrySingle correctJEE Main 2026

Given below are some of the statements about Mn and

\text{Mn}_{2}\text{O}_{7}

. Identify the correct statements A. Mn forms the oxide

\text{Mn}_{2}\text{O}_{7}

in which Mn is in its highest oxidation state. B. Oxygen stabilizes the Mn in higher oxidation states by forming multiple bonds with Mn C.

\text{Mn}_{2}\text{O}_{7}

is an ionic oxide. D. The structure of

\text{Mn}_{2}\text{O}_{7}

consists of one bridged oxygen. Choose the correct answer from the options given below:

(A)A, B, C and D
(B)A, B and D Only
(C)A, C and D Only
(D)A, B and C Only

Q22·ChemistryNumericalJEE Main 2026

Consider the following reactions: NaCl+K

_2

Cr

_2

O

_7

+H

_2

SO

_4

→A+KHSO

_4

+NaHSO

_4

+H

_2

O A + NaOH → B + NaCl + H

_2

O B + H

_2

SO

_4

+ H

_2

O

_2

→ C + Na

_2

SO

_4

+ H

_2

O In the product 'C', 'X' is the number of O

_2^{2-}

units, 'Y' is the total number oxygen atoms present and 'Z' is the oxidation state of Cr. The value of X + Y + Z is ________ .

Q23·ChemistryMultiple correctJEE Advanced 2025

The pair(s) of diamagnetic ions is(are)

(A) $La^{3+}, Ce^{4+}$
(B) $Yb^{2+}, Lu^{3+}$
(C) $La^{2+}, Ce^{3+}$
(D) $Yb^{3+}, Lu^{2+}$

Q24·ChemistrySingle correctJEE Advanced 2025

One of the products formed from the reaction of permanganate ion with iodide ion in neutral aqueous medium is

(A) $I_2$
(B) $IO_3^-$
(C) $IO_4^-$
(D) $IO_2^-$

Q25·ChemistrySingle correctJEE Main 2025

The correct decreasing order of spin only magnetic moment (BM) of

Cu^+

,

Cu^{2+}

,

Cr^{2+}

and

Cr^{3+}

ions is:

(A) $Cu^+>Cu^{2+}>Cr^{2+}>Cr^{3+}$
(B) $Cu^{2+}>Cu^+>Cr^{2+}>Cr^{3+}$
(C) $Cr^{2+}>Cr^{3+}>Cu^{2+}>Cu^+$
(D) $Cr^{3+}>Cr^{2+}>Cu^{2+}>Cu^+$

Q26·ChemistrySingle correctJEE Main 2025

The first transition series metal M has the highest enthalpy of atomisation in its series. One of its aquated ion (

M^{2+}

) exists in green colour. The nature of the oxide formed by the above

M^{2+}

ion is:

(A)neutral
(B)acidic
(C)basic
(D)amphoteric

Q27·ChemistrySingle correctJEE Main 2025

The number of valence electrons present in the metal among Cr, Co, Fe and Ni which has the lowest enthalpy of atomisation is

(A)8
(B)9
(C)6
(D)10

Q28·ChemistrySingle correctJEE Main 2025

Pair of transition metal ions having the same number of unpaired electrons is:

(A) $V^{2+}, Co^{2+}$
(B) $Ti^{2+}, Co^{2+}$
(C) $Fe^{3+}, Cr^{2+}$
(D) $Ti^{3+}, Mn^{2+}$

Q29·ChemistrySingle correctJEE Main 2025

The incorrect relationship in the following pairs in relation to ionisation enthalpies is:

(A) $Mn^+ < Cr^+$
(B) $Mn^{2+} < Mn^+$
(C) $Fe^{2+} < Fe^{3+}$
(D) $Mn^{2+} < Fe^{2+}$

Q30·ChemistrySingle correctJEE Main 2025

'X' is the number of electrons in

t_{2g}

orbitals of the most stable complex ion among

[Fe(NH_3)_6]^{3+}

,

[Fe(Cl)_6]^{3-}

,

[Fe(C_2O_4)_3]^{3-}

and

[Fe(H_2O)_6]^{3+}

. The nature of oxide of vanadium of the type

V_2O_x

is:

(A)Acidic
(B)Neutral
(C)Basic
(D)Amphoteric

Q31·ChemistryIntegerJEE Main 2025

Among Sc, Mn, Co and Cu, identify the element with highest enthalpy of atomisation. The spin only magnetic moment value of that element in its +2 oxidation state is __________ BM (in nearest integer).

Q32·ChemistrySingle correctJEE Main 2025

The metal ions that have the calculated spin only magnetic moment value of 4.9 B.M. are: (A)

Cr^{2+}

(B)

Fe^{2+}

(C)

Fe^{3+}

(D)

Co^{3+}

(E)

Mn^{2+}

. Choose the correct answer from the options given below:

(A)(A), (C) and (E) only
(B)(A), (D) and (E) only
(C)(B) and (E) only
(D)(A), (B) and (E) only

Q33·ChemistrySingle correctJEE Main 2025

Given below are two statements: Statement I:

CrO_3

is a stronger oxidizing agent than

MoO_3

. Statement II: Cr(VI) is more stable than Mo(VI). In the light of the above statements, choose the correct answer from the options given below:

(A)Statement I is false but Statement II is true
(B)Statement I is true but Statement II is false
(C)Both Statement I and Statement II are true
(D)Both Statement I and Statement II are false

Q34·ChemistryIntegerJEE Main 2025

Consider the following reactions:

A+NaCl+H_2SO_4(\text{little amount})\to CrO_2Cl_2+\text{Side Products}

;

CrO_2Cl_2(\text{vapour})+NaOH\to B+NaCl+H_2O

;

B+H^+\to C+H_2O

. The number of terminal 'O' present in the compound 'C' is __________.

Q35·ChemistryIntegerJEE Main 2025

The spin-only magnetic moment value of

M^{n+}

ion formed among Ni, Zn, Mn and Cu that has the least enthalpy of atomisation is ______. (in nearest integer)

Q36·ChemistryIntegerJEE Main 2025

The molar mass of the water insoluble product formed from the fusion of chromite ore (FeCr

_2

O

_4

) with Na

_2

CO

_3

in presence of O

_2

is ______ g mol

^{-1}

.

Q37·ChemistrySingle correctJEE Main 2025

The correct option with order of melting points of the pairs (Mn, Fe), (Tc, Ru) and (Re, Os) is:

(A)Fe < Mn, Ru < Tc and Re < Os
(B)Mn < Fe, Tc < Ru and Re < Os
(C)Mn < Fe, Tc < Ru and Os < Re
(D)Fe < Mn, Ru < Tc and Os < Re

Q38·ChemistrySingle correctJEE Main 2025

The metal ion whose electronic configuration is not affected by the nature of the ligand and which gives a violet colour in non-luminous flame under hot condition in borax bead test is

(A)Ti $^{3+}$
(B)Ni $^{2+}$
(C)Mn $^{2+}$
(D)Cr $^{3+}$

Q39·ChemistrySingle correctJEE Main 2025

Which of the following oxidation reactions are carried out by both K

_2

Cr

_2

O

_7

and KMnO

_4

in acidic medium? A. I

^-\to

I

_2

B. S

^{2-}\to

S C. Fe

^{2+}\to

Fe

^{3+}

D. I

^-\to

IO

_3^-

E. S

_2

O

_3^{2-}\to

SO

_4^{2-}

. Choose the correct answer from the options given below:

(A)B, C and D only
(B)A, D and E only
(C)A, B and C only
(D)C, D and E only

Q40·ChemistryIntegerJEE Main 2025

The spin only magnetic moment (

\mu

) value (B.M.) of the compound with strongest oxidising power among Mn

_2

O

_3

, TiO and VO is ______ B.M. (Nearest integer).

Q41·ChemistrySingle correctJEE Main 2025

Consider 'n' is the number of lone pair of electrons present in the equatorial position of the most stable structure of ClF

_3

. The ions from the following with 'n' number of unpaired electrons are: A. V

^{3+}

B. Ti

^{3+}

C. Cu

^{2+}

D. Ni

^{2+}

E. Ti

^{2+}

. Choose the correct answer from the options given below:

(A)A and C only
(B)A, D and E only
(C)B and C only
(D)B and D only

Q42·ChemistrySingle correctJEE Main 2025

The amphoteric oxide among V

_2

O

_3

, V

_2

O

_4

and V

_2

O

_5

upon reaction with alkali leads to formation of an oxide anion. The oxidation state of V in the oxide anion is:

(A)+3
(B)+7
(C)+5
(D)+4

Q43·ChemistrySingle correctJEE Main 2025

Which of the following ions is the strongest oxidizing agent ? (Atomic Number of Ce = 58, Eu = 63, Tb = 65, Lu = 71)

(A) $Lu^{3+}$
(B) $Eu^{2+}$
(C) $Tb^{4+}$
(D) $Ce^{3+}$

Q44·ChemistrySingle correctJEE Main 2025

Preparation of potassium permanganate from MnO₂ involves two step process in which the 1st step is a reaction with KOH and KNO₃ to produce

(A) $K_4[Mn(OH)_6]$
(B) $K_3MnO_4$
(C) $KMnO_4$
(D) $K_2MnO_4$

Q45·ChemistrySingle correctJEE Main 2025

Match List-I (Transition metal ion) with List-II (Spin only magnetic moment B.M.). Choose the correct answer from the options given below:

List-I (Transition metal ion)	List-II (Spin only magnetic moment B.M.)
A. $Ti^{3+}$	I.3.87
B. $V^{2+}$	II.0.00
C. $Ni^{2+}$	III.1.73
D. $Sc^{3+}$	IV.2.84

(A)(A)-(III), (B)-(I), (C)-(II), (D)-(IV)
(B)(A)-(III), (B)-(I), (C)-(IV), (D)-(II)
(C)(A)-(IV), (B)-(II), (C)-(III), (D)-(I)
(D)(A)-(II), (B)-(IV), (C)-(I), (D)-(III)

Q46·ChemistrySingle correctJEE Main 2025

The correct set of ions (aqueous solution) with same colour from the following is :

(A)V²⁺, Cr³⁺, Mn³⁺
(B)Zn²⁺, V³⁺, Fe³⁺
(C)Ti⁴⁺, V⁴⁺, Mn²⁺
(D)Sc³⁺, Ti³⁺, Cr²⁺

Q47·ChemistrySingle correctJEE Main 2025

Consider the following reactions:

K_2Cr_2O_7\xrightarrow{KOH,\,-H_2O}[A]\xrightarrow{H_2SO_4,\,-H_2O}[B]+K_2SO_4

. The products [A] and [B], respectively are :

(A) $K_2Cr(OH)_4$ and $Cr_2O_3$
(B) $K_2CrO_4$ and $Cr_2O_3$
(C) $K_2CrO_4$ and $K_2Cr_2O_7$
(D) $K_2CrO_4$ and $CrO$

Q48·ChemistrySingle correctJEE Main 2025

Lanthanoid ions with 4f⁷ configuration are: (A) Eu²⁺ (B) Gd³⁺ (C) Eu³⁺ (D) Tb³⁺ (E) Sm²⁺. Choose the correct answer from the options given below:

(A)(A) and (B) only
(B)(A), (B) and (E) only
(C)(B) and (E) only
(D)(B) and (D) only

Q49·ChemistryIntegerJEE Main 2025

Niobium (Nb) and ruthenium (Ru) have 'x' and 'y' number of electrons in their respective 4d orbitals. The value of x + y is ______.

Q50·ChemistryNumericalJEE Main 2024

A transition metal 'M' among Sc, Ti, V, Cr, Mn and Fe has the highest second ionisation enthalpy. The spin-only magnetic moment value of

M^{+}

ion is _______ BM (nearest integer). (Given atomic number Sc: 21, Ti: 22, V: 23, Cr: 24, Mn: 25, Fe: 26)

Q51·ChemistrySingle correctJEE Main 2024

The electronic configuration of Einsteinium is: (Given atomic number of Einsteinium = 99)

(A) $[Rn]5f^{12}6d^{0}7s^{2}$
(B) $[Rn]5f^{11}6d^{0}7s^{2}$
(C) $[Rn]5f^{13}6d^{0}7s^{2}$
(D) $[Rn]5f^{11}6d^{1}7s^{2}$

Q52·ChemistrySingle correctJEE Main 2024

Given below are two statements: Statement I: The higher oxidation states are more stable down the group among transition elements unlike p-block elements. Statement II: Copper can not liberate hydrogen from weak acids. In the light of the above statements, choose the correct answer from the options given below:

(A)Both Statement I and Statement II are false
(B)Statement I is false but Statement II is true
(C)Both Statement I and Statement II are true
(D)Statement I is true but Statement II is false

Q53·ChemistryNumericalJEE Main 2024

Number of colourless lanthanoid ions among the following is _____.

Eu^{3+}, Lu^{3+}, Nd^{3+}, La^{3+}, Sm^{3+}

Q54·ChemistrySingle correctJEE Main 2024

The electronic configuration of Cu(II) is

3d^9

whereas that of Cu(I) is

3d^{10}

. Which of the following is correct ?

(A)Cu(II) is less stable
(B)Stability of Cu(I) and Cu(II) depends on nature of copper salts
(C)Cu(II) is more stable
(D)Cu(I) and Cu(II) are equally stable

Q55·ChemistrySingle correctJEE Main 2024

The equilibrium

\text{Cr}_2\text{O}_7^{2-}\rightleftharpoons 2\text{CrO}_4^{2-}

is shifted to the right in:

(A)an acidic medium
(B)a basic medium
(C)a weakly acidic medium
(D)a neutral medium

Q56·ChemistryNumericalJEE Main 2024

The "spin only" magnetic moment value of

MO_4^{2-}

is ___ BM. (Where M is a metal having least metallic radii among Sc, Ti, V, Cr, Mn and Zn). (Given atomic number: Sc

=21

, Ti

=22

, V

=23

, Cr

=24

, Mn

=25

and Zn

=30

)

Q57·ChemistrySingle correctJEE Main 2024

Given below are two statements: Statement (I): Fusion of

\text{MnO}_2

with KOH and an oxidising agent gives dark green

\text{K}_2\text{MnO}_4

. Statement (II): Manganate ion on electrolytic oxidation in alkaline medium gives permanganate ion. In the light of the above statements, choose the correct answer from the options given below.

(A)Both Statement I and Statement II is true
(B)Both Statement I and Statement II is false
(C)Statement I is true but Statement II is false
(D)Statement I is false but Statement II is true

Q58·ChemistrySingle correctJEE Main 2024

The number of elements from the following that do not belong to lanthanoids is:

Eu

,

Cm

,

Er

,

Tb

,

Yb

and

Lu

.

(A)3
(B)4
(C)1
(D)5

Q59·ChemistryNumericalJEE Main 2024

Among

VO_2^{+}

,

MnO_4^{-}

and

Cr_2O_7^{2-}

, the spin-only magnetic moment value of the species with least oxidising ability is _______ BM (Nearest integer). (Given atomic number V = 23, Mn = 25, Cr = 24)

Q60·ChemistryNumericalJEE Main 2024

Among CrO,

Cr_2O_3

and

CrO_3

, the sum of spin-only magnetic moment values of the basic and amphoteric oxides is _______

\times10^{-2}

BM (nearest integer). (Given atomic number of Cr is 24)

Q61·ChemistryNumericalJEE Main 2024

The difference in the 'spin-only' magnetic moment values of

KMnO_4

and the manganese product formed during titration of

KMnO_4

against oxalic acid in acidic medium is _______ BM (nearest integer).

Q62·ChemistrySingle correctJEE Main 2024

Arrange the following elements in the increasing order of number of unpaired electrons in it. (A) Sc (B) Cr (C) V (D) Ti (E) Mn. Choose the correct answer from the options given below:

(A)(C) < (E) < (B) < (A) < (D)
(B)(B) < (C) < (D) < (E) < (A)
(C)(A) < (D) < (C) < (B) < (E)
(D)(A) < (D) < (C) < (E) < (B)

Q63·ChemistryNumericalJEE Main 2024

The spin-only magnetic moment value of the ion among

\text{Ti}^{2+}

,

\text{V}^{2+}

,

\text{Co}^{3+}

and

\text{Cr}^{2+}

that acts as a strong oxidising agent in aqueous solution is ___ BM (nearest integer). (Given atomic numbers: Ti = 22, V = 23, Cr = 24, Co = 27)

Q64·ChemistrySingle correctJEE Main 2024

The metal that shows the highest and maximum number of oxidation states is:

(A)Fe
(B)Mn
(C)Ti
(D)Co

Q65·ChemistrySingle correctJEE Main 2024

While preparing crystals of Mohr's salt, dil.

\text{H}_2\text{SO}_4

is added to a mixture of ferrous sulphate and ammonium sulphate before dissolving this mixture in water. Dil.

\text{H}_2\text{SO}_4

is added here to:

(A)prevent the hydrolysis of ferrous sulphate
(B)prevent the hydrolysis of ammonium sulphate
(C)make the medium strongly acidic
(D)increase the rate of formation of crystals

Q66·ChemistrySingle correctJEE Main 2024

The number of ions from the following that have the ability to liberate hydrogen from a dilute acid is:

\text{Ti}^{2+}

,

\text{Cr}^{2+}

and

\text{V}^{2+}

.

(A)0
(B)2
(C)3
(D)1

Q67·ChemistryNumericalJEE Main 2024

The fusion of chromite ore with sodium carbonate in the presence of air leads to the formation of products A and B along with the evolution of

\text{CO}_2

. The sum of the spin-only magnetic moment values of A and B is __________ B.M. (Nearest integer). (Given atomic numbers: C: 6, Na: 11, O: 8, Fe: 26, Cr: 24)

Q68·ChemistryNumericalJEE Main 2024

In a borax bead test under hot condition, a metal salt (one from the given) is heated at point B of the flame (shown in the figure), resulting in a green-coloured bead. The spin-only magnetic moment value of the salt is ___ (nearest integer). [Given atomic numbers: Cu = 29, Ni = 28, Mn = 25, Fe = 26]

Q69·ChemistryNumericalJEE Main 2024

A first row transition metal with highest enthalpy of atomisation, upon reaction with oxygen at high temperature forms oxides of formula

\text{M}_2\text{O}_n

(where

n=3,4,5

). The 'spin-only' magnetic moment value of the amphoteric oxide from the above metal is ______ BM (nearest integer).

Q70·ChemistrySingle correctJEE Main 2024

A first row transition metal in its

+2

oxidation state has a spin-only magnetic moment value of 3.86 BM. The atomic number of the metal is

(A)25
(B)26
(C)22
(D)23

Q71·ChemistrySingle correctJEE Main 2024

The element which shows only one oxidation state other than its elemental form is:

(A)Cobalt
(B)Scandium
(C)Titanium
(D)Nickel

Q72·ChemistryNumericalJEE Main 2024

Consider the following reaction

MnO_2+KOH+O_2\to A+H_2O

. Product "A" in neutral or acidic medium disproportionate to give products "B" and "C" along with water. The sum of spin-only magnetic moment values of B and C is ___ BM. (nearest integer) (Given atomic number of Mn is

25

)

Q73·ChemistrySingle correctJEE Main 2024

Given below are two statements: one is labelled as Assertion (A) and the other is labelled as Reason (R). Assertion (A): In aqueous solutions

\text{Cr}^{2+}

is reducing and

\text{Mn}^{3+}

is oxidising in nature. Reason (R): Extra stability to half filled electronic configuration is observed than incompletely filled electronic configuration. In the light of the above statement, choose the most appropriate answer from the options given below:

(A)Both (A) and (R) are true and (R) is the correct explanation of (A)
(B)Both (A) and (R) are true but (R) is not the correct explanation of (A)
(C)(A) is false but (R) is true
(D)(A) is true but (R) is false

Q74·ChemistrySingle correctJEE Main 2024

Which of the following compounds show colour due to d–d transition?

(A) $\text{CuSO}_4\cdot 5\text{H}_2\text{O}$
(B) $\text{K}_2\text{Cr}_2\text{O}_7$
(C) $\text{K}_2\text{CrO}_4$
(D) $\text{KMnO}_4$

Q75·ChemistrySingle correctJEE Main 2024

The transition metal having highest

3^{\text{rd}}

ionisation enthalpy is:

(A)Cr
(B)Mn
(C)V
(D)Fe

Q76·ChemistrySingle correctJEE Main 2024

Choose the correct statements from the following A.

Mn_2O_7

is an oil at room temperature B.

V_2O_4

reacts with acid to give

VO_2^+

C.

CrO

is a basic oxide D.

V_2O_5

does not react with acid Choose the correct answer from the options given below:

(A)A, B and D only
(B)A and C only
(C)A, B and C only
(D)B and C only

Q77·ChemistrySingle correctJEE Main 2024

Identify correct statements from below: A. The chromate ion is square planar. B. Dichromates are generally prepared from chromates. C. The green manganate ion is diamagnetic. D. Dark green coloured

K_2MnO_4

disproportionates in a neutral or acidic medium to give permanganate. E. With increasing oxidation number of transition metal, ionic character of the oxides decreases. Choose the correct answer from the options given below:

(A)B, C, D only
(B)A, D, E only
(C)A, B, C only
(D)B, D, E only

Q78·ChemistryNumericalJEE Main 2024

In the reaction of potassium dichromate, potassium chloride and sulfuric acid (conc.), the oxidation state of the chromium in the product is

(+)

______.

Q79·ChemistrySingle correctJEE Main 2024

Diamagnetic Lanthanoid ions are:

(A) $Nd^{3+}$ and $Eu^{3+}$
(B) $La^{3+}$ and $Ce^{4+}$
(C) $Nd^{3+}$ and $Ce^{4+}$
(D) $Lu^{3+}$ and $Eu^{3+}$

Q80·ChemistrySingle correctJEE Main 2024

The orange colour of

K_2Cr_2O_7

and purple colour of

KMnO_4

is due to:

(A)Charge transfer transition in both.
(B) $d$ - $d$ transition in $KMnO_4$ and charge transfer transitions in $K_2Cr_2O_7$ .
(C) $d$ - $d$ transition in $K_2Cr_2O_7$ and charge transfer transition in $KMnO_4$ .
(D) $d$ - $d$ transition in both.

Q81·ChemistrySingle correctJEE Main 2024

Match List-I with List-II. Choose the correct answer from the options given below:

List-I (Species)	List-II (Electronic distribution)
A. $Cr^{2+}$	I. $3d^8$
B. $Mn^{+}$	II. $3d^3 4s^1$
C. $Ni^{2+}$	III. $3d^4$
D. $V^{+}$	IV. $3d^5 4s^1$

(A)(A)-I, (B)-II, (C)-III, (D)-IV
(B)(A)-III, (B)-IV, (C)-I, (D)-II
(C)(A)-IV, (B)-III, (C)-I, (D)-II
(D)(A)-II, (B)-I, (C)-IV, (D)-III

Q82·ChemistrySingle correctJEE Main 2024

Alkaline oxidative fusion of

MnO_2

gives "A" which on electrolytic oxidation in alkaline solution produces B. A and B respectively are:

(A) $Mn_2O_3$ and $MnO_4^-$
(B) $MnO_4^{2-}$ and $MnO_4^-$
(C) $Mn_2O_3$ and $MnO_4^{2-}$
(D) $MnO_4^{2-}$ and $Mn_2O_3$

Q83·ChemistrySingle correctJEE Main 2024

A and B formed in the following reactions are:

CrO_2Cl_2 + 4NaOH \rightarrow A + 2NaCl + 2H_2O

A + 2HCl + 2H_2O_2 \rightarrow B + 3H_2O

(A) $A = Na_2CrO_4,\ B = CrO_5$
(B) $A = Na_2Cr_2O_7,\ B = CrO_4$
(C) $A = Na_2Cr_2O_7,\ B = CrO_3$
(D) $A = Na_2Cr_2O_7,\ B = CrO_5$

Q84·ChemistrySingle correctJEE Main 2024

KMnO_4

decomposes on heating at 513 K to form

O_2

along with

(A) $MnO_2$ & $K_2O_2$
(B) $K_2MnO_4$ & Mn
(C)Mn & $KO_2$
(D) $K_2MnO_4$ & $MnO_2$

Q85·ChemistrySingle correctJEE Main 2024

In chromyl chloride test for confirmation of

Cl^-

ion, a yellow solution is obtained. Acidification of the solution and addition of amyl alcohol and 10%

H_2O_2

turns organic layer blue indicating formation of chromium pentoxide. The oxidation state of chromium in that is

(A) $+6$
(B) $+5$
(C) $+10$
(D) $+3$

Q86·ChemistrySingle correctJEE Main 2024

Which of the following statements are correct about Zn, Cd and Hg? A. They exhibit high enthalpy of atomization as the d-subshell is full. B. Zn and Cd do not show variable oxidation state while Hg shows +I and +II. C. Compounds of Zn, Cd and Hg are paramagnetic in nature. D. Zn, Cd and Hg are called soft metals. Choose the most appropriate from the options given below:

(A)B, D only
(B)B, C only
(C)A, D only
(D)C, D only

Q87·ChemistrySingle correctJEE Main 2024

The correct IUPAC name of

K_2MnO_4

is:

(A)Potassium tetraoxopermanganate (VI)
(B)Potassium tetraoxidomanganate (VI)
(C)Dipotassium tetraoxidomanganate (VII)
(D)Potassium tetraoxidomanganese (VI)

Q88·ChemistrySingle correctJEE Main 2024

Which of the following acts as a strong reducing agent? (Atomic number: Ce = 58, Eu = 63, Gd = 64, Lu = 71)

(A) $Lu^{3+}$
(B) $Gd^{3+}$
(C) $Eu^{2+}$
(D) $Ce^{4+}$

Q89·ChemistrySingle correctJEE Main 2024

Identify the incorrect pair from the following : (1) Photography – AgBr (2) Polythene preparation –

TiCl_4

,

Al(CH_3)_3

(3) Rubber process – Pt (4) Wacker process –

PtCl_2

(A)Photography – AgBr
(B)Polythene preparation – $TiCl_4$ , $Al(CH_3)_3$
(C)Rubber process – Pt
(D)Wacker process – $PtCl_2$

Q90·ChemistrySingle correctJEE Main 2024

NaCl reacts with conc.

\text{H}_2\text{SO}_4

and

\text{K}_2\text{Cr}_2\text{O}_7

to give reddish fumes (B), which react with NaOH to give yellow solution (C). (B) and (C) respectively are:

(A) $\text{CrO}_2\text{Cl}_2,\;\text{Na}_2\text{CrO}_4$
(B) $\text{Na}_2\text{CrO}_4,\;\text{CrO}_2\text{Cl}_2$
(C) $\text{CrO}_2\text{Cl}_2,\;\text{KHSO}_4$
(D) $\text{CrO}_2\text{Cl}_2,\;\text{Na}_2\text{Cr}_2\text{O}_7$

Q91·ChemistrySingle correctJEE Main 2024

Given below are two statements : Statement (I) : In the Lanthanoids, the formation of

Ce^{+4}

is favoured by its noble gas configuration. Statement (II) :

Ce^{+4}

is a strong oxidant reverting to the common +3 state. In the light of the above statements, choose the most appropriate answer from the options given below :

(A)Statement I is false but Statement II is true
(B)Both Statement I and Statement II are true
(C)Statement I is true but Statement II is false
(D)Both Statement I and Statement II are false

Q92·ChemistrySingle correctJEE Main 2024

Consider the following complex ions

P=[\text{FeF}_6]^{3-}

,

Q=[\text{V}(\text{H}_2\text{O})_6]^{2+}

,

R=[\text{Fe}(\text{H}_2\text{O})_6]^{2+}

. The correct order of the complex ions, according to their spin only magnetic moment values (in B.M.) is:

(A) $R<Q<P$
(B) $R<P<Q$
(C) $Q<R<P$
(D) $Q<P<R$

Q93·ChemistrySingle correctJEE Main 2024

Choose the correct option having all the elements with

d^{10}

electronic configuration from the following :

(A) $_{27}$ Co, $_{28}$ Ni, $_{24}$ Cr
(B) $_{29}$ Cu, $_{30}$ Zn, $_{48}$ Cd, $_{47}$ Ag
(C) $_{46}$ Pd, $_{28}$ Ni, $_{26}$ Fe, $_{24}$ Cr
(D) $_{28}$ Ni, $_{24}$ Cr, $_{26}$ Fe, $_{29}$ Cu

Q94·ChemistrySingle correctJEE Main 2024

Which of the following electronic configuration would be associated with the highest magnetic moment?

(A) $[\text{Ar}]\,3d^7$
(B) $[\text{Ar}]\,3d^8$
(C) $[\text{Ar}]\,3d^3$
(D) $[\text{Ar}]\,3d^6$

Q95·ChemistrySingle correctJEE Advanced 2023

In the scheme given below, X and Y, respectively, are

(A) $\mathrm{CrO_4^{2-}}$ and $\mathrm{Br_2}$
(B) $\mathrm{MnO_4^{2-}}$ and $\mathrm{Cl_2}$
(C) $\mathrm{MnO_4^{-}}$ and $\mathrm{Cl_2}$
(D) $\mathrm{MnSO_4}$ and $\mathrm{HOCl}$

Q96·ChemistryNumericalJEE Main 2023

In Chromyl chloride, the oxidation state of chromium is (+)_______

Q97·ChemistrySingle correctJEE Main 2023

The pair of lanthanides in which both elements have high third-ionization energy is:

(A)Eu, Gd
(B)Eu, Yb
(C)Lu, Yb
(D)Dy, Gd

Q98·ChemistrySingle correctJEE Main 2023

Given below are two statements: one is labelled as Assertion A and the other is labelled as Reason R. Assertion A: 5f electrons can participate in bonding to a far greater extent than 4f electrons. Reason R: 5f orbitals are not as buried as 4f orbitals. In the light of the above statements, choose the correct answer from the options given below:

(A)Both A and R are true but R is NOT the correct explanation of A
(B)Both A and R are true and R is the correct explanation of A
(C)A is false but R is true
(D)A is true but R is false

Q99·ChemistrySingle correctJEE Main 2023

Which of the following statements are correct? (A) The M

^{3+}

/M

^{2+}

reduction potential for iron is greater than manganese. (B) The higher oxidation states of first row d-block elements get stabilized by oxide ion. (C) Aqueous solution of Cr

^{2+}

can liberate hydrogen from dilute acid. (D) Magnetic moment of V

^{2+}

is observed between 4.4-5.2 BM. Choose the correct answer from the options given below:

(A)(B), (C) only
(B)(C), (D) only
(C)(A), (B), (D) only
(D)(A), (B) only

Q100·ChemistrySingle correctJEE Main 2023

Prolonged heating is avoided during the preparation of ferrous ammonium sulphate to

(A)prevent oxidation
(B)prevent reduction
(C)prevent hydrolysis
(D)prevent breaking

Q101·ChemistrySingle correctJEE Main 2023

In chromyl chloride, the number of d-electrons present on chromium is same as in (Given at. no. of Ti : 22, V : 23, Cr : 24, Mn : 25, Fe : 26)

(A)Ti (III)
(B)Fe (III)
(C)V (IV)
(D)Mn (VII)

Q102·ChemistryNumericalJEE Main 2023

In ammonium-phosphomolybdate, the oxidation state of Mo is

+

_____.

Q103·ChemistrySingle correctJEE Main 2023

Strong reducing and oxidizing agents among the following, respectively, are:

(A) $Eu^{2+}$ and $Yb^{2+}$
(B) $Ce^{3+}$ and $Tb^{4+}$
(C) $Ce^{4+}$ and $Tb^{4+}$
(D) $Eu^{2+}$ and $Ce^{4+}$

Q104·ChemistrySingle correctJEE Main 2023

Highest oxidation state of Mn is exhibited in

\text{Mn}_2\text{O}_7

. The correct statements about

\text{Mn}_2\text{O}_7

are: (A) Mn is tetrahedrally surrounded by oxygen atoms. (B) Mn is octahedrally surrounded by oxygen atoms. (C) Contains Mn-O-Mn bridge. (D) Contains Mn-Mn bond. Choose the correct answer from the options given below:

(A)A and C only
(B)A and D only
(C)B and C only
(D)B and D only

Q105·ChemistrySingle correctJEE Main 2023

Given below are two statements: one is labelled as Assertion (A) and the other is labelled as Reason (R). Assertion (A):

Cu^{2+}

in water is more stable than

Cu^{+}

. Reason (R): Enthalpy of hydration for

Cu^{2+}

is much less than that of

Cu^{+}

. In the light of the above statements, choose the correct answer from the options given below:

(A)Both (A) and (R) are correct and (R) is the correct explanation of (A)
(B)(A) is not correct but (R) is correct
(C)(A) is correct but (R) is not correct
(D)Both (A) and (R) are correct but (R) is not the correct explanation of (A)

Q106·ChemistrySingle correctJEE Main 2023

Given below are two statements: one is labelled as Assertion (A) and the other is labelled as Reason (R). Assertion (A): The first ionization enthalpy of 3d series elements is more than that of group 2 metals. Reason (R): In 3d series of elements successive filling of d-orbitals takes place. In the light of the above statements, choose the correct answer from the options given below:

(A)Both (A) and (R) are true but (R) is not the correct explanation of (A)
(B)Both (A) and (R) are true and (R) is the correct explanation of (A)
(C)(A) is true but (R) is false
(D)(A) is false but (R) is true

Q107·ChemistrySingle correctJEE Main 2023

Which of the following elements have half-filled f-orbitals in their ground state? (Given atomic number Sm=62; Eu=63; Tb=65; Gd=64; Pm=61) A. Sm B. Eu C. Tb D. Gd E. Pm. Choose the correct answer from the options given below:

(A)A and B only
(B)A and E only
(C)C and D only
(D)B and D only

Q108·ChemistrySingle correctJEE Main 2023

Nd^{2+}

=

(A) $4f^3$
(B) $4f^46s^2$
(C) $4f^4$
(D) $4f^26s^2$

Q109·ChemistrySingle correctJEE Main 2023

The correct order of basicity of oxides of vanadium is

(A) $V_2O_5 > V_2O_4 > V_2O_3$
(B) $V_2O_4 > V_2O_3 > V_2O_5$
(C) $V_2O_3 > V_2O_5 > V_2O_4$
(D) $V_2O_3 > V_2O_4 > V_2O_5$

Q110·ChemistrySingle correctJEE Main 2023

A solution of

CrO_5

in amyl alcohol has a _______ colour.

(A)Green
(B)Orange-Red
(C)Yellow
(D)Blue

Q111·ChemistrySingle correctJEE Main 2023

The set of correct statements is: (i) Manganese exhibits

+7

oxidation state in its oxide. (ii) Ruthenium and Osmium exhibit

+8

oxidation in their oxides. (iii) Sc shows

+4

oxidation state which is oxidizing in nature. (iv) Cr shows oxidising nature in

+6

oxidation state.

(A)(ii) and (iii)
(B)(i), (ii) and (iv)
(C)(ii), (iii) and (iv)
(D)(i) and (iii)

Q112·ChemistryNumericalJEE Main 2023

How many of the following metal ions have similar value of spin only magnetic moment in gaseous state? (Given atomic number: V, 23; Cr, 24; Fe, 26; Ni, 28)

V^{3+}, Cr^{3+}, Fe^{2+}, Ni^{3+}

. The number is _______.

Q113·ChemistrySingle correctJEE Main 2023

The magnetic moment of a transition metal compound has been calculated to be 3.87 B.M. The metal ion is:

(A) $\text{Cr}^{2+}$
(B) $\text{Ti}^{2+}$
(C) $\text{V}^{2+}$
(D) $\text{Mn}^{2+}$

Q114·ChemistrySingle correctJEE Main 2023

Which one amongst the following are good oxidizing agents? (A)

Sm^{2+}

(B)

Ce^{2+}

(C)

Ce^{4+}

(D)

Tb^{4+}

. Choose the most appropriate answer from the options given below:

(A)D only
(B)C only
(C)C and D only
(D)A and B only

Q115·ChemistrySingle correctJEE Main 2023

K_2Cr_2O_7

paper acidified with dilute

H_2SO_4

turns green when exposed to

(A)Carbon dioxide
(B)Sulphur trioxide
(C)Sulphur dioxide
(D)Hydrogen sulphide

Q116·ChemistrySingle correctJEE Main 2022

In following pairs, the one in which both transition metal ions are colourless is :

(A) $Sc^{3+}$ , $Zn^{2+}$
(B) $Ti^{4+}$ , $Cu^{2+}$
(C) $V^{2+}$ , $Ti^{3+}$
(D) $Zn^{2+}$ , $Mn^{2+}$

Q117·ChemistrySingle correctJEE Main 2022

Which of the following 3d-metal ion will give the lowest enthalpy of hydration (Δ

_{hyd}

H) when dissolved in water ?

(A)Cr $^{2+}$
(B)Mn $^{2+}$
(C)Fe $^{2+}$
(D)Co $^{2+}$

Q118·ChemistryNumericalJEE Main 2022

The disproportionation of MnO

_4^{2-}

in acidic medium resulted in the formation of two manganese compounds A and B. If the oxidation state of Mn in B is smaller than that of A, then the spin-only magnetic moment (μ) value of B in BM is __________. (Nearest integer)

Q119·ChemistrySingle correctJEE Main 2022

Which of the following has least tendency to liberate H

_2

from mineral acids ?

(A)Cu
(B)Mn
(C)Ni
(D)Zn

Q120·ChemistrySingle correctJEE Main 2022

Which of the following pair is not isoelectronic species? (At. no. Sm, 62; Er, 68: Yb, 70: Lu, 71; Eu, 63: Tb, 65; Tm, 69)

(A) $\mathrm{Sm^{2+}}$ and $\mathrm{Er^{3+}}$
(B) $\mathrm{Yb^{2+}}$ and $\mathrm{Lu^{3+}}$
(C) $\mathrm{Eu^{2+}}$ and $\mathrm{Tb^{4+}}$
(D) $\mathrm{Tb^{2+}}$ and $\mathrm{Tm^{4+}}$

Q121·ChemistrySingle correctJEE Main 2022

Given below are two statements: Statement I : Iron (III) catalyst, acidified

K_{2}Cr_{2}O_{7}

and neutral

KMnO_{4}

have the ability to oxidise

I^{-}

to

I_{2}

independently. Statement II: Manganate ion is paramagnetic in nature and involves pπ –pπ bonding. In the light of the above statements, choose the correct answer from the options.

(A)Both statement I and Statement II are ture
(B)Both statement I and Statement II are false
(C)Statement I is true but Statement II is false
(D)Statement I is false but Statement II is true

Q122·ChemistrySingle correctJEE Main 2022

In neutral or alkaline solution, MnO

_{4}^{-}

oxidises thiosulphate to:

(A)S $_{2}$ O $_{7}^{2-}$
(B)S $_{2}$ O $_{8}^{2-}$
(C)SO $_{3}^{2-}$
(D)SO $_{4}^{2-}$

Q123·ChemistrySingle correctJEE Main 2022

The total number of Mn = O bonds in

Mn_{2}O_{7}

is ____

(A)4
(B)5
(C)6
(D)3

Q124·ChemistryNumericalJEE Main 2022

The oxidation state of manganese in the product obtained in a reaction of potassium permanganate and hydrogen peroxide in basic medium is______.

Q125·ChemistryNumericalJEE Main 2022

The spin-only magnetic moment value of the compound with strongest oxidizing ability among

MnF_{4}

,

MnF_{3}

and

MnF_{2}

is ______ B.M. [nearest integer]

Q126·ChemistryNumericalJEE Main 2022

Among

Co^{3+}

,

Ti^{2+}

,

V^{2+}

and

Cr^{2+}

ions, one if used as a reagent cannot liberate

H_{2}

from dilute mineral acid solution, its spin-only magnetic moment in gaseous state is ……B.M. (Nearest integer)

Q127·ChemistryNumericalJEE Main 2022

An acidified manganate solution undergoes disproportionation reaction. The spin-only magnetic moment value of the product having manganese in higher oxidation state is _______ B.M. (Nearest integer)

Q128·ChemistryNumericalJEE Main 2022

The number of terminal oxygen atoms present in the product B obtained from the following reaction is _______ .

FeCr_2O_4

+

Na_2CO_3

+

O_2

→ A +

Fe_2O_3

+

CO_2

A +

H^+

→ B +

H_2O

+

Na^+

Q129·ChemistrySingle correctJEE Main 2022

The electronic configuration of Pt (atomic number 78) is:

(A)[Xe] $4f^{14} 5d^9 6s^1$
(B)[Kr] $4f^{14} 5d^{10}$
(C)[Xe] $4f^{14} 5d^{10}$
(D)[Xe] $4f^{14} 5d^8 6s^2$

Q130·ChemistrySingle correctJEE Main 2022

Which one of the lanthanoids given below is the most stable in divalent form?

(A)Ce (Atomic Number 58)
(B)Sm (Atomic Number 62)
(C)Eu (Atomic Number 63)
(D)Yb (Atomic Number 70)

Q131·ChemistrySingle correctJEE Main 2022

In 3d series, the metal having the highest M

^{2+}

/M standard electrode potential is

(A)Cr
(B)Fe
(C)Cu
(D)Zn

Q132·ChemistryNumericalJEE Main 2022

The number of statement(s) correct from the following for copper (at no. 29) is/are _______ (A) Cu(II) complexes are always paramagnetic (B) Cu(I) complexes are generally colourless (C) Cu(I) is easily oxidized (D) In Fehling solution, the active reagent has Cu(I)

Q133·ChemistryNumericalJEE Main 2022

Acidified potassium permanganate solution oxidises oxalic acid. The spin-only magnetic moment of the manganese product formed from the above reaction is ______ B.M. (Nearest Integer)

Q134·ChemistrySingle correctJEE Main 2022

The 'f' orbitals are half and completely filled, respectively in lanthanide ions (Given: Atomic no. Eu, 63; Sm, 62; Tm, 69; Tb, 65; Yb, 70; Dy, 66]

(A)Eu $^{2+}$ and Tm $^{2+}$
(B)Sm $^{2+}$ and Tm $^{3+}$
(C)Tb $^{4+}$ and Yb $^{2+}$
(D)Dy $^{3+}$ and Yb $^{3+}$

Q135·ChemistrySingle correctJEE Main 2022

The most common oxidation state of Lanthanoid elements is +3. Which of the following is likely to deviate easily from +3 oxidation state?

(A)Ce (At. No. 58)
(B)La (At. No. 57)
(C)Lu (At. No. 71)
(D)Gd (At. No. 64)

Q136·ChemistryNumericalJEE Main 2022

The spin–only magnetic moment value of the most basic oxide of vanadium among

V_{2}O_{3}

,

V_{2}O_{4}

and

V_{2}O_{5}

is ______ B.M. (Nearest Integer)

Q137·ChemistrySingle correctJEE Main 2022

The metal ion (in gaseous state) with lowest spin-only magnetic moment value is

(A)V $^{2+}$
(B)Ni $^{2+}$
(C)Cr $^{2+}$
(D)Fe $^{2+}$

Q138·ChemistrySingle correctJEE Main 2022

Among the following, which is the strongest oxidizing agent ?

(A) $Mn^{3+}$
(B) $Fe^{3+}$
(C) $Ti^{3+}$
(D) $Cr^{3+}$

Q139·ChemistrySingle correctJEE Main 2022

Cerium (IV) has a noble gas configuration. Which of the following is correct statement about it?

(A)It will not prefer to undergo redox reactions.
(B)It will prefer to gain electron and act as an oxidizing agent
(C)It will prefer to give away an electron and behave as reducing agent
(D)It acts as both, oxidizing and reducing agent.

Q140·ChemistryNumericalJEE Main 2022

Manganese (VI) has ability to disproportionate in acidic solution. The difference in oxidation states of two ions it forms in acidic solution is_______

Q141·ChemistryNumericalJEE Main 2022

The difference in oxidation state of chromium in chromate and dichromate salts is ________

Q142·ChemistrySingle correctJEE Main 2021

In the given chemical reaction, colors of the Fe

^{2+}

and Fe

^{3+}

ions, are respectively : 5Fe

^{2+}

+ MnO

_{4}^{-}

+ 8H

^{+}

→ Mn

^{2+}

+ 4H

_{2}

O + 5Fe

^{3+}

(A)Yellow, Orange
(B)Yellow, Green
(C)Green, Orange
(D)Green, Yellow

Q143·ChemistrySingle correctJEE Main 2021

Identify the element for which electronic configuration in +3 oxidation state is [Ar]3d

^{5}

:

(A)Ru
(B)Mn
(C)Co
(D)Fe

Q144·ChemistrySingle correctJEE Main 2021

The

\mathrm{Eu^{2+}}

ion is a strong reducing agent in spite of its ground state electronic configuration (outermost) : [Atomic number of Eu = 63]

(A) $4f^{7}6s^{2}$
(B) $4f^{6}$
(C) $4f^{7}$
(D) $4f^{6}6s^{2}$

Q145·ChemistrySingle correctJEE Main 2021

Which one of the following lanthanides exhibits +2 oxidation state with diamagnetic nature ? (Given Z for Nd = 60, Yb = 70, La = 57, Ce = 58)

(A)Nd
(B)Yb
(C)La
(D)Ce

Q146·ChemistrySingle correctJEE Main 2021

In the structure of the dichromate ion, there is a :

(A)linear symmetrical Cr–O–Cr bond.
(B)non-linear symmetrical Cr–O–Cr bond.
(C)linear unsymmetrical Cr–O–Cr bond.
(D)non-linear unsymmetrical Cr–O–Cr bond.

Q147·ChemistrySingle correctJEE Main 2021

Potassium permanganate on heating at 513 K gives a product which is :

(A)paramagnetic and colourless
(B)diamagnetic and green
(C)diamagnetic and colourless
(D)paramagnetic and green

Q148·ChemistrySingle correctJEE Main 2021

The addition of dilute NaOH to Cr

^{3+}

salt solution will give :

(A)a solution of [Cr(OH) $_{4}$ ] $^{-}$
(B)precipitate of Cr $_{2}$ O $_{3}$ (H $_{2}$ O) $_{n}$
(C)precipitate of [Cr(OH) $_{6}$ ] $^{3-}$
(D)precipitate of Cr(OH) $_{3}$

Q149·ChemistrySingle correctJEE Main 2021

The nature of oxides

\mathrm{V_2O_3}

and CrO is indexed as 'X' and 'Y' type respectively. The correct set of X and Y is:

(A)X = basic Y = amphoteric
(B)X = amphoteric Y = basic
(C)X = acidic Y = acidic
(D)X = basic Y = basic

Q150·ChemistryNumericalJEE Main 2021

The number of

f

electrons in the ground state electronic configuration of Np (Z = 93) is ________ . (Nearest integer)

Q151·ChemistrySingle correctJEE Main 2021

Which one of the following when dissolved in water gives coloured solution in nitrogen atmosphere?

(A) $\mathrm{CuCl_2}$
(B) $\mathrm{AgCl}$
(C) $\mathrm{ZnCl_2}$
(D) $\mathrm{Cu_2Cl_2}$

Q152·ChemistryNumericalJEE Main 2021

The number of

4f

electrons in the ground state electronic configuration of

Gd^{2+}

is _________. [Atomic number of Gd = 64]

Q153·ChemistrySingle correctJEE Main 2021

The spin only magnetic moments (in BM) for free

Ti^{3+}, V^{2+}

and

Sc^{3+}

ions respectively are (At. No. Sc: 21; Ti:22; V:23)

(A)1.73,0,3.87
(B)0,3.87,1.73
(C)3.87,1.73,0
(D)1.73, 3.87,0

Q154·ChemistryNumericalJEE Main 2021

Number of electrons present in 4f orbital of Ho

^{3+}

ion is____________________. (Given atomic number of Ho = 67)

Q155·ChemistrySingle correctJEE Main 2021

The set having ions which are coloured and paramagnetic both is :

(A) $Ni^{2+},Mn^{7+},Hg^{2+}$
(B) $Cu^{+},Zn^{2+},Mn^{4+}$
(C) $Sc^{3+},V^{5+},Ti^{4}$
(D) $Cu^{2+},Cr^{3+},Sc^{+}$

Q156·ChemistrySingle correctJEE Main 2021

Which one of the following species doesn't have a magnetic moment of 1.73 BM, (spin only value)?

(A) $\mathrm{CuI}$
(B) $\mathrm{[Cu(NH_3)_4]Cl_2}$
(C) $\mathrm{O_2^-}$
(D) $\mathrm{O_2^+}$

Q157·ChemistrySingle correctJEE Main 2021

The oxide that shows magnetic property is :

(A)SiO $_{2}$
(B)Mn $_{3}$ O $_{4}$
(C)Na $_{2}$ O
(D)MgO

Q158·ChemistrySingle correctJEE Main 2021

Given below are two statements: Statement I : Potassium permanganate on heating at 573 K forms potassium manganate. Statement II : Both potassium permanganate and potassium manganate are tetrahedral and paramagnetic in nature. In the light of the above statements, choose the most appropriate answer from the options given below:

(A)Statement I is true but statement II is false
(B)Both statement I and statement II are true
(C)Statement I is false but statement II is true
(D)Both statement I and statement II are false

Q159·ChemistryNumericalJEE Main 2021

In the ground state of atomic Fe(Z = 26), the spin-only magnetic moment is ______

\times

10

^{-1}

BM. (Round off to the Nearest Integer). [Given :

\sqrt{3}

= 1.73,

\sqrt{2}

= 1.41]

Q160·ChemistrySingle correctJEE Main 2021

The common positive oxidation states for an element with atomic number 24, are :

(A)+2 to +6
(B)+1 and +3 to +6
(C)+1 and +3
(D)+1 to +6

Q161·ChemistrySingle correctJEE Main 2021

What is the spin-only magnetic moment value (BM) of a divalent metal ion with atomic number 25, in it's aqueous solution?

(A)5.92
(B)5.0
(C)zero
(D)5.26

Q162·ChemistrySingle correctJEE Main 2021

Arrange the following metal complex/compounds in the increasing order of spin only magnetic moment. Presume all the three, high spin system. (Atomic numbers Ce = 58, Gd = 64 and Eu = 63.) (a) (NH

_{4}

)

_{2}

[Ce(NO

_{3}

)

_{6}

] (b) Gd(NO

_{3}

)

_{3}

and (c) Eu(NO

_{3}

)

_{3}

Answer is :

(A)(b) < (a) < (c)
(B)(c) < (a) < (b)
(C)(a) < (b) < (c)
(D)(a) < (c) < (b)

Q163·ChemistrySingle correctJEE Main 2021

Fex

_{2}

and Fey

_{3}

are known when x and y are :

(A)x = F, Cl, Br, I and y = F, Cl, Br
(B)x = F, Cl, Br and y = F, Cl, Br, I
(C)x = Cl, Br, I and y = F, Cl, Br, I
(D)x = F, Cl, Br, I and y = F, Cl, Br, I

Q164·ChemistrySingle correctJEE Main 2021

Given below are two statement : one is labelled as Assertion A and the other is labelled as Reason R : Assertion A : Size of Bk

^{3+}

ion is less than Np

^{3+}

ion. Reason R : The above is a consequence of the lanthanoid contraction. In the light of the above statements, choose the correct answer from the options given below :

(A)A is false but R is true
(B)Both A and R are true but R is not the correct explanation of A
(C)Both A and R are true and R is the correct explanation of A
(D)A is true but R is false

Q165·ChemistrySingle correctJEE Main 2021

Given below are two statements : Statement I : The E° value of Ce

^{4+}

/ Ce

^{3+}

is + 1.74 V. Statement II : Ce is more stable in Ce

^{4+}

state than Ce

^{3+}

state. In the light of the above statements, choose the most appropriate answer from the options given below :

(A)Both statement I and statement II are correct
(B)Statement I is incorrect but statement II is correct
(C)Both statement I and statement II are incorrect
(D)Statement I is correct but statement II is incorrect

Q166·ChemistryNumericalJEE Main 2021

Dichromate ion is treated with base, the oxidation number of Cr in the product formed is :

Q167·ChemistrySingle correctJEE Main 2021

Which one of the following lanthanoids does not form MO

_2

? [M is lanthanoid metal]

(A)Nd
(B)Yb
(C)Dy
(D)Pr

Q168·ChemistrySingle correctJEE Main 2021

Given below are two statements: Statement-I : CeO

_{2}

can be used for oxidation of aldehydes and ketones. Statement-II : Aqueous solution of EuSO

_{4}

is a strong reducing agent.

(A)Statement I is true, statement II is false
(B)Statement I is false, statement II is true
(C)Both Statement I and Statement II are false
(D)Both Statement I and Statement II are true

Q169·ChemistrySingle correctJEE Main 2021

In which of the following pairs, the outer most electronic configuration will be the same?

(A)Fe $^{2+}$ and Co $^{+}$
(B)Cr $^{+}$ and Mn $^{2+}$
(C)Ni $^{2+}$ and Cu $^{+}$
(D)V $^{2+}$ and Cr $^{+}$

Q170·ChemistrySingle correctJEE Main 2021

The major components of German Silver are :

(A)Cu, Zn and Ag
(B)Ge, Cu and Ag
(C)Zn, Ni and Ag
(D)Cu, Zn and Ni

Q171·ChemistryNumericalJEE Main 2021

5 = [1+(2-1)3/4]×0.52 ×m (2) The spin only magnetic moment of a divalent ion in aqueous solution (atomic number 29) is ____BM.

Q172·ChemistrySingle correctJEE Main 2021

The electrode potential of

\mathrm{M^{2+}/M}

of 3d− series elements shows positive value for:

(A)Zn
(B)Co
(C)Fe
(D)Cu

Q173·ChemistrySingle correctJEE Main 2021

What is the correct order of the following elements with respect to their density ?

(A)Cr < Fe < Co < Cu < Zn
(B)Cr < Zn < Co < Cu < Fe
(C)Zn < Cu < Co < Fe < Cr
(D)Zn < Cr < Fe < Co < Cu

Q174·ChemistrySingle correctJEE Main 2021

The incorrect statement among the following is :

(A) $VOSO_{4}$ is a reducing agent
(B)Red colour of ruby is due to the presence of $CO^{3+}$
(C) $Cr_{2}O_{3}$ is an amphoteric oxide
(D) $RuO_{4}$ is an oxidizing agent

Q175·ChemistryIntegerJEE Advanced 2020

An acidified solution of potassium chromate was layered with an equal volume of amyl alcohol. When it was shaken after the addition of 1 mL of 3%

H_{2}O_{2}

, a blue alcohol layer was obtained. The blue color is due to the formation of a chromium (VI) compound 'X'. What is the number of oxygen atoms bonded to chromium through only single bonds in a molecule of X?

Q176·ChemistrySingle correctJEE Main 2020

The lanthanoid that does NOT show +4 oxidation state is:

(A)Dy
(B)Ce
(C)Eu
(D)Tb

Q177·ChemistrySingle correctJEE Main 2020

The INCORRECT statement is:

(A)bronze is an alloy of copper and tin
(B)cast iron is used to manufacture wrought iron
(C)german silver is an alloy of zinc, copper and nickel
(D)brass is an alloy of copper and nickel.

Q178·ChemistrySingle correctJEE Main 2020

The set that contains atomic numbers of only transition elements, is

(A)37, 42, 50, 64
(B)21, 25, 42, 72
(C)9, 17, 34, 38
(D)21, 32, 53, 64

Q179·ChemistrySingle correctJEE Main 2020

Mischmetal is an alloy consisting mainly of:

(A)lanthanoid metals
(B)actinoid and transition metals
(C)lanthanoid and actinoid metals
(D)actionoid metals

Q180·ChemistrySingle correctJEE Main 2020

The correct electronic configuration and spin – only magnetic moment (BM) of

Gd^{3+}

(Z = 64), respectively, are:

(A)[Xe] $4f^7$ and 7.9
(B)[Xe] $4f^7$ and 8.9
(C)[Xe] $5f^7$ and 8.9
(D)[Xe] $5f^7$ and 7.9

Q181·ChemistrySingle correctJEE Main 2020

The incorrect statement(s) among (a) - (c) is (are): (a) W(VI) is more stable than Cr(VI). (b) in the presence of HCl, permanganate titrations provide satisfactory results. (c) some lanthanoid oxides can be used as phosphors.

(A)(b) and (c) only
(B)(a) only
(C)(b) only
(D)(a) and (b) only

Q182·ChemistrySingle correctJEE Main 2020

The incorrect statement is

(A)In manganate and permanganateions, the π - bounding takes place by overlap of p –orbitals of oxygen and d – orbitals of manganese
(B)Manganate ion is green in colour and permanganateion is purple in colour
(C)Manganate and permanganate ions are paramagnetic
(D)Manganate and permanganate ions are tetrahedral

Q183·ChemistrySingle correctJEE Main 2020

The electronic configurations of bivalent europium and trivalent cerium are: (atomic number: Xe = 54, Ce = 58, Eu = 63)

(A)[Xe] 4f $^7$ 6s $^2$ and [Xe] 4f $^2$ 6s $^2$
(B)[Xe] 4f $^7$ and [Xe] 4f $^1$
(C)[Xe] 4f $^2$ and [Xe] 4f $^7$
(D)[Xe] 4f $^4$ and [Xe] 4f $^9$

Q184·ChemistryNumericalJEE Main 2020

The sum of the total number of bonds between chromium and oxygen atoms in chromate and dichromate ions is ________________

Q185·ChemistrySingle correctJEE Main 2020

The third ionization enthalpy is minimum for :

(A)Ni
(B)Co
(C)Mn
(D)Fe

Q186·ChemistryNumericalJEE Main 2020

Consider the following reactions:

\mathrm{NaCl + K_2Cr_2O_7 + H_2SO_4(Conc.) \longrightarrow (A) + side\ products}

\mathrm{(A) + NaOH \longrightarrow (B) + Side\ products}

\mathrm{(B) + H_2SO_4 + H_2O_2(dilute) \longrightarrow (C) + Side\ products}

The sum of the total number of atoms in one molecule each of (A), (B) and (C) is __________

Q187·ChemistryMultiple correctJEE Advanced 2019

Consider the following reactions (unbalanced) Zn + hot conc. H

_{2}

SO

_{4}

\longrightarrow

G + R + X Zn + conc.NaOH

\longrightarrow

T + Q G + H

_{2}

S + NH

_{4}

OH

\longrightarrow

Z(a precipitate) + X + Y Choose the correct option(s)

(A)The oxidation state of Zn in T is +1
(B)R is a V-shaped molecule
(C)Z is dirty white in colour
(D)Bond order of Q is 1 in its ground state

Q188·ChemistryMultiple correctJEE Advanced 2019

Fusion of MnO

_{2}

with KOH in presence of O

_{2}

produces a salt W. Alkaline solution of W upon electrolytic oxidation yields another salt X. The manganese containing ions present in W and X, respectively, are Y and Z. Correct statement(s) is(are)

(A)In aqueous acidic solution, Y undergoes disproportionation reaction to give Z and MnO $_{2}$
(B)In both Y and Z, $\pi$ -bonding occurs between p-orbitals of oxygen and d-orbitals of manganese
(C)Y is diamagnetic in nature while Z is paramagnetic
(D)Both Y and Z are coloured and have tetrahedral shape

Q189·ChemistrySingle correctJEE Main 2019

The pair that has similar atomic radii is:

(A)Ti and Hf
(B)Mn and Re
(C)Sc and Ni
(D)Mo and W

Q190·ChemistrySingle correctJEE Main 2019

Thermal decomposition of a Mn compound (X) at 513 K results in compound Y, MnO

_2

and a gaseous product. MnO

_2

reacts with NaCl and concentrated H

_2

SO

_4

to give a pungent gas Z. X, Y and Z, respectively.

(A)K $_2$ MnO $_4$ , KMnO $_4$ and SO $_2$
(B)K $_3$ MnO $_4$ , K $_2$ MnO $_4$ and Cl $_2$
(C)K $_2$ MnO $_4$ , KMnO $_4$ and Cl $_2$
(D)KMnO $_4$ , K $_2$ MnO $_4$ and Cl $_2$

Q191·ChemistrySingle correctJEE Main 2019

The highest possible oxidation states of uranium and plutonium, respectively, are

(A)6 and 4
(B)7 and 6
(C)4 and 6
(D)6 and 7

Q192·ChemistrySingle correctJEE Main 2019

The correct order of the first ionization enthalpies is

(A)Mn < Ti < Zn < Ni
(B)Zn < Ni < Mn < Ti
(C)Ti < Mn < Zn < Ni
(D)Ti < Mn < Ni < Zn

Q193·ChemistrySingle correctJEE Main 2019

Consider the hydrated ions of Ti

^{2+}

, V

^{2+}

, Ti

^{3+}

and Sc

^{3+}

. The correct order of their spin-only magnetic moments is:

(A)Ti $^{3+}$ < T $^{2+}$ < Sc $^{3+}$ < V $^{2+}$
(B)Sc $^{3+}$ < Ti $^{3+}$ < Ti $^{2}$ < V $^{2+}$
(C)V $^{2+}$ < Ti $^{2+}$ < Ti $^{3+}$ < Sc $^{3+}$
(D)Sc $^{3+}$ < Ti $^{3+}$ < V $^{2+}$ < Ti $^{2+}$

Q194·ChemistrySingle correctJEE Main 2019

The maximum number of possible oxidation states of actinoids are shown by

(A)berkelium (Bk) and californium (Cf)
(B)nobelium (No) and lawrencium (Lr)
(C)actinium (Ac) and thorium (Th)
(D)neptunium (Np) and plutonium (Pu)

Q195·ChemistrySingle correctJEE Main 2019

The lanthanoide that would show colour is:

(A) $Gd^{3+}$
(B) $La^{3+}$
(C) $Lu^{3+}$
(D) $Sm^{3+}$

Q196·ChemistrySingle correctJEE Main 2019

The statement that is INCORRECT about the interstitial compound is:

(A)they have metallic conductivity
(B)they have high melting points
(C)they are chemically reactive
(D)they are very hard

Q197·ChemistrySingle correctJEE Main 2019

The correct order of atomic radii is :

(A)Nd > Ce > Eu > Ho
(B)Ho > Nd > Eu > Ce
(C)Ce > Eu > Ho > Nd
(D)Eu > Ce > Nd > Ho

Q198·ChemistrySingle correctJEE Main 2019

The element the usually does NOT show variable oxidation states is:

(A)Cu
(B)Ti
(C)Sc
(D)V

Q199·ChemistrySingle correctJEE Main 2019

\underline{A}

\xrightarrow{4KOH,O_2}

2

\underline{B}

+ 2 H

_2

O (Green) 3

\underline{B}

\xrightarrow{4HCl}

2

\underline{C}

+ MnO

_2

+ 2H

_2

O (Purple) 2

\underline{C}

\xrightarrow{H_2O,KI}

2

\underline{A}

+ 2KOH +

\underline{D}

In the above sequence of reactions,

\underline{A}

and

\underline{D}

, respectively are:

(A)Ki and KMnO $_4$
(B)MnO $_2$ and KIO $_3$
(C)KIO $_3$ and MnO $_2$
(D)KI and K $_2$ MnO $_4$

Q200·ChemistrySingle correctJEE Main 2019

The effect of lanthanoid contraction in the lanthanoid series of elements by the large means

(A)increase in both atomic and ionic radii
(B)decrease in atomic radii and increase in ionic radii
(C)decrease in both atomic and ionic radii
(D)increase in atomic radii and decrease in ionic radii

Q201·ChemistrySingle correctJEE Main 2019

The transition element that has lowest enthalpy of atomisation is

(A)Fe
(B)Cu
(C)V
(D)Zn

Q202·ChemistryMultiple correctJEE Advanced 2015

The correct statement(s) about

\mathrm{Cr^{2+}}

and

\mathrm{Mn^{3+}}

is(are) [Atomic numbers of Cr = 24 and Mn = 25]

(A) $\mathrm{Cr^{2+}}$ is a reducing agent
(B) $\mathrm{Mn^{3+}}$ is an oxidizing agent
(C)Both $\mathrm{Cr^{2+}}$ and $\mathrm{Mn^{3+}}$ exhibit $d^{4}$ electronic configuration
(D)When $\mathrm{Cr^{2+}}$ is used as a reducing agent, the chromium ion attains $d^{5}$ electronic configuration

d- and f-Block Elements — JEE Previous Year Questions

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