Question

Oxidation number of Fe in $\left[Fe\right(CN{)}_6{]}^{-3},\left[Fe\right(CN{)}_6{]}^{-4}$ respectively would be :

• A. +3, +2
• B. +3, +3
• C. +3, -2
• D. +2, +2

Answer 1

The correct option is A +3, +2

Let oxidation number of Fe be 'x' in $\left[Fe\right(CN{)}_6{]}^{3-}$
$\text{charge on}C{N}^{-}=-1$
$\Rightarrow x-6=-3$
$\Rightarrow x=+3$
Let oxidation number of Fe be 'x' in $\left[Fe\right(CN{)}_6{]}^{4-}$
$\text{charge on}C{N}^{-}=-1$
$\Rightarrow x-6=-4$
$\Rightarrow x=+2$