Question

47. A complex compound in which the oxidation number of a metal is
zero is :

(1) K [Fe(CN)6]
(2) K[Fe(CN)6]
(3) [Ni(CO4)]
(4) [PI (NH3)4]Cl2
​

Answer 1

A complex compound in which the oxidation number of a metal is

zero is :

[Ni(CO4)]

Answer 2

Answer:

(3) Ni(CO4)

Explanation:

Its simple, as carbonyls (CO) has no charge on it the oxidation number will be zero.