Question

What is meant by ‘disproportionation’ of an oxidation state? Give an example.

Answer 1

$\text{Disproportionation}$
When a particular oxidation state becomes less stable relative to other oxidation states, one lower, one higher, it is said to undergo disproportionation.

$\text{Example}$
Manganese $\left(VI\right)$ becomes unstable relative to manganese $\left(VII\right)$ and manganese $\left(IV\right)$ in acidic solution.

$3\stackrel{+6}{Mn}{O}_4^{2-}+4H^{+}\to 2\stackrel{+7}{Mn}{O}_4^{-}+\stackrel{+4}{Mn}{O}_2+2H_{2}O$