Question

In which of the following compounds, transition metal may have zero oxidation state ?

• A. $\left[Fe\right(CO{)}_5]$
• B. $\left[Ni\right(CN{)}_4{]}^{2-}$
• C. $F{e}_2{O}_3$
• D. $Cr{O}_5$

Answer 1

Answer: (A)

$\left[Fe\right(CO{)}_5]$

Option (A) is correct.
(A): $\left[Fe\right(CO{)}_5]$ have zero oxidation state
$x+0\times 5=0$
$x=0$
(B): $\left[Ni\right(CN{)}_4{]}^{2-}$ have $+2$ oxidation state
$x+(-1\times 4)=(-2)$
$=+2$
(C): $F{e}_2{O}_3$ have $+3$ oxidation state
$2x+(-2\times 3)=0$
$=+3$
(D): $Cr{O}_5$ have $+6$ oxidation state