Question

In carbon monoxide ,due to dative bond presence the oxidation state of carbon is not considered as 2.then how much(oxidation number)

Answer 1

Oxidation number is the charge left on the central atom when all the bonding pairs of electrons are removed, with the charge devolved to the most electronegative atom. For Ni(CO)4, we break the Ni−CO bond and we get Ni0 +4×−:C≡O+. And thus nickel has a formal oxidation state of ZERO.