Mn3+ changes to Mn2+ and MnO2 in acidic medium is which type of reaction?

Oxidation reaction Reduction reaction Disproportionation reaction None of these

Disproportionation reaction

Mn3+ disproportionate to Mn2+ and MnO2 in acidic medium. 3Mn3+ + 2H2O → Mn2+ + MnO2 + 4H+     +3                               +2             +4