Question

Which of the following is diamagnetic in nature?

• A. $\left[Fe\right(CN{)}_6{]}^{3-}$
• B. $NiC{l}_4^{2-}$
• C. $\left[Ni\right(CO{)}_4]$
• D. $[MnC{l}_4{]}^{2-}$

Answer 1

The correct option is C $\left[Ni\right(CO{)}_4]$

Diamagnetic substance have all paired electron.
(a) [Fe(CN)6]3− Oxidation state of Fe=+3
It has one unpaired electron and is paramagnetic.
(b) It has two unpaired electrons and is paramagnetic
(c) It has no unpaired electron and is diamagnetic
(d) ∴ It is paramagnetic as it has five unpaired electrons.