Question

Which of the following statements is incorrect?

• A. $\left[ MnCl _6\right]^{3-}$ is more paramagnetic than $\left[ Mn ( CN )_6\right]^{3-}$
• B. Both $\left[ Co \left( C _2 O _4\right)_3\right]^{3-}$ and $\left[ CoF _6\right]^{3-}$ are paramagnetie.
• C. $\left[ Fe ( CN )_6\right]^{3-}$ forms inner orbital complex whereas $\left[ FeF _6\right]^{3-}$ forms outer orbital complex.
• D. Both (a) and (b).

Answer 1

Answer: (B)

$\left[ Co \left( C _2 O _4\right)_3\right]^{3-}$ is dimagnetic as oxalate is a strong ligand causing pairing of $3 d$ electrons in $Co ^{3+}$ thereby leading to $d^2 s p^3$ hybridisation.