Chemistry · Coordination Compounds

JEE Advanced 2020 — Paper 1 — Question 21

Choose the correct statement(s) among the following:

Option A:
$\left[\mathrm{FeCl}_{4}\right]^{-}$ has tetrahedral geometry
Correct
Option B:
$\left.[\mathrm{Co}(\mathrm{en}))\left(\mathrm{NH}_{3}\right)_{2} \mathrm{Cl}_{2}\right]^{+}$ has 2 geometrical isomers
Option C:
$\left[\mathrm{FCl}_{4}\right]^{-}$ has higher spin - only magnetic moment than $\left.[\mathrm{Co}(\mathrm{en}))\left(\mathrm{NH}_{3}\right)_{2} \mathrm{Cl}_{2}\right]^{+}$
Correct
Option D:
The cobalt ion in $\left.[\mathrm{Co}(\mathrm{en}))\left(\mathrm{NH}_{3}\right)_{2} \mathrm{Cl}_{2}\right]^{+}$ has $\mathrm{sp}^{3} \mathrm{~d}^{2}$ hybridization

Answer: A, C

Step-by-step solution

(A) $\left[\mathrm{FeCl}_{4}\right]^{-}: \underset{\left(\mathrm{d}^{5}\right)}{3+}$ , weak ligand, so tetrahedral.

(B) $\left[\mathrm{Co}(\mathrm{en})\left(\mathrm{NH}_{3}\right)_{2} \mathrm{Cl}_{2}\right]^{+}$ : Three geometrical isomers.

$\left[\mathrm{Co}(\mathrm{en})\left(\mathrm{NH}_{3}\right)_{2} \mathrm{Cl}_{2}\right]^{+}: \mathrm{Co}^{3+}\left(\mathrm{d}^{6}\right)$ , diamagnetic

(D) $\left[\mathrm{Co}(\mathrm{en})\left(\mathrm{NH}_{3}\right)_{2} \mathrm{Cl}_{2}\right]^{+}: \mathrm{d}^{2} \mathrm{sp}^{3} \cdot \mathrm{~N}=0, \mu=0 \&\left[\mathrm{FeCl}_{4}\right]^{-} \Rightarrow$ Tetrahedral $\left(\mathrm{sp}^{3}\right)$

Answer key and solution verified before publishing.

Practise Coordination Compounds

Start with this question, then two more from the same chapter — with a tutor that explains every step. Free.

Solve a similar one free

Exam: JEE Advanced 2020
Paper: Paper 1
Subject: Chemistry
Chapter: Coordination Compounds
Topic: Isomerism in Coordination Compounds