JEE Main 2021 — Chemistry Inorganic Chemistry

2021mcqeasy

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

Official previous-year question

Held on 25 Feb 2021 · Verified 6 Jul 2026.

Options

A
${\mathrm{Cr}}^{+}\text{and }{\mathrm{Mn}}^{2+}$
B
${\mathrm{Ni}}^{2+}\text{ and }{\mathrm{Cu}}^{+}$
C
${\mathrm{Fe}}^{2+}\text{ and }{\mathrm{Co}}^{+}$
D
${V}^{2+}\text{ and }{\mathrm{Cr}}^{+}$

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Solution

Option 1: ${\mathrm{Mn}}^{+2}[\mathrm{Ar}]3{d}^{5},{\mathrm{Cr}}^{+}[\mathrm{Ar}]3{d}^{5}$

Cr is expected to have the highest second ionization enthalpy as after removal of 4s electrons, the electrons will be removed from d-orbital. Cr+ have stable half-filled d-orbital with maximum spin multiplicity.

Option $-2{\mathrm{Ni}}^{+2}[\mathrm{Ar}]3{d}^{8},{\mathrm{Cu}}^{+}[\mathrm{Ar}]3{d}^{10}$

Option $-3{\mathrm{Fe}}^{+2}[\mathrm{Ar}]3{d}^{6},{\mathrm{Co}}^{+}[\mathrm{Ar}]3{d}^{7}4{s}^{1}$

Option $-4{V}^{+2}[\mathrm{Ar}]3{d}^{3},{\mathrm{Cr}}^{+}[\mathrm{Ar}]3{d}^{5}$

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JEE Main Inorganic Chemistry in other years

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JEE Main 2021 — Chemistry Inorganic Chemistry

2021mcqeasy

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

Official previous-year question

Held on 25 Feb 2021 · Verified 6 Jul 2026.

Options

A
${\mathrm{Cr}}^{+}\text{and }{\mathrm{Mn}}^{2+}$
B
${\mathrm{Ni}}^{2+}\text{ and }{\mathrm{Cu}}^{+}$
C
${\mathrm{Fe}}^{2+}\text{ and }{\mathrm{Co}}^{+}$
D
${V}^{2+}\text{ and }{\mathrm{Cr}}^{+}$

Did you get this right?

Solution

Option 1: ${\mathrm{Mn}}^{+2}[\mathrm{Ar}]3{d}^{5},{\mathrm{Cr}}^{+}[\mathrm{Ar}]3{d}^{5}$

Option $-2{\mathrm{Ni}}^{+2}[\mathrm{Ar}]3{d}^{8},{\mathrm{Cu}}^{+}[\mathrm{Ar}]3{d}^{10}$

Option $-3{\mathrm{Fe}}^{+2}[\mathrm{Ar}]3{d}^{6},{\mathrm{Co}}^{+}[\mathrm{Ar}]3{d}^{7}4{s}^{1}$

Option $-4{V}^{+2}[\mathrm{Ar}]3{d}^{3},{\mathrm{Cr}}^{+}[\mathrm{Ar}]3{d}^{5}$

Your note

JEE Main Inorganic Chemistry in other years

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Work through every JEE Main Inorganic Chemistry PYQ, year by year.

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JEE Main 2021 — Chemistry Inorganic Chemistry

Options

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Solution

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JEE Main Inorganic Chemistry in other years

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Physical Chemistry

Organic Chemistry

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JEE Main 2021 — Chemistry Inorganic Chemistry

Options

Did you get this right?

Solution

Your note

JEE Main Inorganic Chemistry in other years

More JEE Main Inorganic Chemistry questions

Other Chemistry topics for JEE Main

Physical Chemistry

Organic Chemistry

Keep practicing Inorganic Chemistry