Question

Oxidation state of iron in $Fe(CO{)}_4$ is :

• A. $+1$
• B. $-1$
• C. $+2$
• D. $0$

Answer 1

The correct option is D $0$

In the formation of metal carbonyls, two types of bond are formed. Initially, carbonyl ligand $\left(CO\right)$ donates its electron pair to the central metal atom due to which metal gets a negative charge which makes it unstable. Hence the metal again forms back bonding with the ligand and due to which the net result is the zero charge on metal atom.