KMnO4 is a strong oxidizing agent in both acidic and basic medium
In acid medium
MnO4– (Pink) + 8H+ + 5e- → Mn2+ (colourless) + 4H2O
Eg : (a) Acidified KMnO4 oxidises Fe2+ to Fe3+
MnO4- + 5Fe2+ + 8H+ → Mn2+ + 5Fe3+ + 4H2O
(b) Oxalate ion is oxidized to CO2 by acidified KMnO4.
2MnO4- +5C2O42-+ 16H+ → 2Mn2++ 2CO2 +7H2O
In basic medium
MnO4– is reduced to MnO2
MnO4 - + 2H2O + 3e- → MnO2 + 4OH-
Eg: Alkaline KMnO4 oxidises I- to IO3-
2MnO4- + I- + H2O → 2MnO2 + IO3- + 2OH-
