JEE Main 2024 — Chemistry Inorganic Chemistry

2024mcqmedium

${[\mathrm{Co}{({\mathrm{NH}}_{3})}_{6}]}^{3+}$ and ${[{\mathrm{CoF}}_{6}]}^{3-}$ are respectively known as:

Official previous-year question

Held on 1 Feb 2024 · Verified 6 Jul 2026.

Options

A
Spin free Complex, Spin paired Complex
B
Spin paired Complex, Spin free Complex
C
Outer orbital Complex, Inner orbital Complex
D
Inner orbital Complex, Spin paired Complex

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Solution

In the complex ${[\mathrm{Co}{({\mathrm{NH}}_{3})}_{6}]}^{3+}$ Ammonia is strong field ligand and electronic configuration of

${\mathrm{Co}}^{3+}$ $\Rightarrow 3{d}^{6}({t}_{2g}^{6},{e}_{g}^{0})$

Hybridisation: ${d}^{2}{\mathrm{sp}}^{3}$

Pairing of electrons takes place due to the strong field ligand. Hence, it is inner orbital complex (spin paired complex).

In the complex ${[{\mathrm{CoF}}_{6}]}^{3-}$ fluoride is weak field ligand and electronic configuration of ${\mathrm{Co}}^{3+}$ $\Rightarrow 3{d}^{6}({t}_{2g}^{4},{e}_{g}^{2})$ .

Hybridisation: ${\mathrm{sp}}^{3}{d}^{2}$

Pairing of electrons not takes place due to the weak field ligand. Hence, it is outer orbital complex (spin free complex).

Hence option B is the answer.

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Solution

In the complex ${[\mathrm{Co}{({\mathrm{NH}}_{3})}_{6}]}^{3+}$ Ammonia is strong field ligand and electronic configuration of

${\mathrm{Co}}^{3+}$ $\Rightarrow 3{d}^{6}({t}_{2g}^{6},{e}_{g}^{0})$

Hybridisation: ${d}^{2}{\mathrm{sp}}^{3}$

Pairing of electrons takes place due to the strong field ligand. Hence, it is inner orbital complex (spin paired complex).

In the complex ${[{\mathrm{CoF}}_{6}]}^{3-}$ fluoride is weak field ligand and electronic configuration of ${\mathrm{Co}}^{3+}$ $\Rightarrow 3{d}^{6}({t}_{2g}^{4},{e}_{g}^{2})$ .

Hybridisation: ${\mathrm{sp}}^{3}{d}^{2}$

Pairing of electrons not takes place due to the weak field ligand. Hence, it is outer orbital complex (spin free complex).

Hence option B is the answer.

JEE Main 2024 — Chemistry Inorganic Chemistry

Options

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JEE Main 2024 — 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

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