Question

Oxidation state of iron in $N{a}_2\left[Fe\right(CN{)}_5\left(NO\right)]$ is:

• A. $+1$
• B. $+2$
• C. $0$
• D. $+3$

Answer 1

Answer: (D)

$+3$

Let $x$ be the oxidation number of $Fe$.
The oxidation numbers of $N{a}^{+},C{N}^{-}$, $NO$ and are $+1,-1,0$ respectively.
The sum of the oxidation numbers is zero.
Hence, $2(+1)+x+5(-1)+0=0$ or $x=+3$.
Thus, the oxidation state of iron in $N{a}_2\left[Fe\right(CN{)}_5\left(NO\right)]$ is $+3$.