Question

What is the oxidation state of Ni in Ni(CO)₄?

Answer 1

Ni(CO)₄ oxidation state of Ni is:

CO (carbonyl) is a neutral ligand (no charge).

Let the oxidation state of Ni be x.

The total charge on the complex is 0.

So,

x + 4(0) = 0

x = 0

In Ni(CO)₄, the oxidation state of Ni is 0.