Question

Out of $\left[Fe\right(CN{)}_6{]}^{4-},\left[Ni\right(CN{)}_4{]}^{2-}$ and $\left[Ni\right(CO{)}_4]$ :

• A. all have identical geometry
• B. all are paramagnetic
• C. all are diamagnetic
• D. $\left[Fe\right(CN{)}_6{]}^{4-}$ is diamagnetic but $\left[Ni\right(CN{)}_4{]}^{2-}$ and $\left[Ni\right(CN{)}_4]$ are paramagnetic

Answer 1

The correct option is C all are diamagnetic

As $C{N}^{-}$ and CO both are strong ligand so in presence of these ligands, pairing of electron happens.
So they all compounds dont have unpaired electron and they all are diamagnetic.