Q40 · CSIR NET Chemistry, June 2016
Paper: CSIR NET June 2016 · Subject: Inorganic Chemistry · Chapter: Coordination Chemistry · Topic: Magnetism · Marks: 2 · Difficulty: Hard
Paramagnetic susceptibility of the order of $10^{-6}\ \mathrm{cm}^{3}\mathrm{mol}^{-1}$ observed for $\mathrm{KMnO}_{4}$ is due to-
(a)random spin alignment
(c)paramagnetic impurity
(b)antiferromagnetic exchange interaction
(d)temperature independent paramagnetism
Answer
Answer: D ✓ checked by 4AB · confidence high
The source book printed no answer; this one was worked out and checked — see the explanation.
Explanation
Mn(VII) in KMnO₄ is d⁰, so there are no unpaired spins; the small, temperature-independent susceptibility (~10⁻⁶ cm³ mol⁻¹) is TIP, a second-order Zeeman mixing of excited states.
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