Question

Predict the magnetic nature of $A$ and $B$.
(a) Both are diamagnetic
(b) A is diamagnetic and B is paramagnetic with one unpaired electron
(c) A is diamagnetic and B is paramagnetic with two unpaired electrons
(d) Both are paramagnetic

• A. Both are diamagnetic
• B. A is diamagnetic and B is paramagnetic with one unpaired
  electron
  
• C. A is diamagnetic and B is paramagnetic with two unpaired
  electrons
  
• D. Both are paramagnetic

Answer 1

Answer: (C)

$A$ is diamagnetic, square planar complex because of strong ligand field of $C{N}^{-}.$

$B$ is paramagnetic, tetrahedral complex because of weak ligand field of $C{l}^{-}.$