Potassium Permanganate ($KMn{O}_4$) is one of the most powerful oxidizing agents.

• In Acidic Medium: The Permanganate ion ($Mn{O}_4^{-}$) is reduced to the Manganous ion ($M{n}^{2+}$).
• Half-reaction: $Mn{O}_4^{-}+8H^{+}+5e^{-}\to M{n}^{2+}+4H_{2}O$
• The oxidation state of $Mn$ changes from $+7$ to $+2$. The large gain of electrons ($n=5$) explains its extreme oxidizing power in acidic solutions compared to neutral or basic ones.