The oxidation number of cobalt in `K [Co(CO)_(4)]` is

Options

A. `+1`
B. `+3`
C. `-1`
D. `-3`

Answer

C

Explanation

Oxidation no. of (CO) in a complex is zero. `K[Co(CO)_4 ]implies1 + x = 4(0) = 0 implies x =-1`