Chemistry · Coordination Compounds

JEE Main 2025 — 23 January, Morning Shift — Question 36

The complex that shows Facial - Meridional isomerism is

Option A:
$\left[\mathrm{Co}\left(\mathrm{NH}_{3}\right)_{3} \mathrm{Cl}_{3}\right]$
Correct
Option B:
$\left[\mathrm{Co}\left(\mathrm{NH}_{3}\right)_{4} \mathrm{Cl}_{2}\right]^{+}$
Option C:
$\left[\mathrm{Co}(\mathrm{en})_{3}\right]^{3+}$
Option D:
$\left[\mathrm{Co}(\mathrm{en})_{2} \mathrm{Cl}_{2}\right]^{+}$

Answer: A

$\mathrm{Ma}_{3} \mathrm{~b}_{3}$ type complexes show Facial - Meridional isomerism

(i) $\left[\mathrm{Co}\left(\mathrm{NH}_{3}\right)_{3} \mathrm{Cl}_{3}\right] \Rightarrow \mathrm{Ma}_{3} \mathrm{~b}_{3}$

(ii) $\left[\mathrm{Co}\left(\mathrm{NH}_{3}\right)_{4} \mathrm{Cl}_{2}\right]^{+} \Rightarrow \mathrm{Ma}_{4} \mathrm{~b}_{2}$

(iii) $\left[\mathrm{Co}(\mathrm{en})_{3}\right]^{3+} \quad \Rightarrow \mathrm{M}(\mathrm{AA})_{3}$

(iv) $\left[\mathrm{Co}(\mathrm{en})_{2} \mathrm{Cl}_{2}\right]^{+} \Rightarrow \mathrm{M}(\mathrm{AA})_{2} \mathrm{~b}_{2}$

$\mathrm{a}, \mathrm{b},=\mathrm{NH}_{3}, \mathrm{Cl}^{-}$

$\mathrm{AA}=\mathrm{en}$

Answer key and solution verified before publishing.

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