Potassium permanganate ($ ext{KMnO}_4$) is prepared commercially from pyrolusite ore ($ ext{MnO}_2

Question

Potassium permanganate ($	ext{KMnO}_4$) is prepared commercially from pyrolusite ore ($	ext{MnO}_2$). What are the oxidation states of manganese in the intermediate manganate ion and the final permanganate ion, respectively?

Professor PC Thomas Classes · Answer

Fusion of $	ext{MnO}_2$ with KOH gives the green manganate ion ($	ext{MnO}_4^{2-}$), where Mn is in the +6 state. Disproportionation or electrolytic oxidation of manganate yields the purple permanganate ion ($	ext{MnO}_4^-$), where Mn is in the +7 state.