# Why is KMnO_4 an oxidizing agent?

Aug 11, 2016

Because manganese metal is in its highest oxidation state ($M n \left(V I I +\right)$, and it is likely to be reduced in any reaction.
And if it is likely to be reduced, it is an electron sink, and therefore an $\text{oxidizing agent}$. Typically, permanganate is reduced to colourless $M {n}^{2 +}$:
$M n {O}_{4}^{-} + 8 {H}^{+} + 5 {e}^{-} \rightarrow M {n}^{2 +} + 4 {H}_{2} O$
Mass and charge are balanced here, so at least the reaction is viable. The macroscopic change is usually from deeply purple permanganate to almost colourless $M {n}^{2 +}$ ion, so this reaction is convenient in that it is self-indicating.