It acts as an oxidising as well as reducing agent in both acidic and alkaline media. Simple reactions are described below.
1.Oxidising action in acidic medium
2Fe2+ (aq) + 2H+ (aq) + H2O2 (aq) → 2Fe3+ (aq) + 2H2O (l)
PbS (s) + 4H2O2 (aq) → PbSO4 (s) + 4H2O (l)
2.Reducing action in acidic medium
2MnO4- + 6H+ + 5H2O2 → 2Mn 2+ + 8H2O + 5O2
HOCl + H2O2 → H3O+ +Cl- + O2
3.Oxidising action in basic medium
2Fe2+ (aq) + H2O2 (aq) → 2Fe3+ (aq) + 2OH- (l)
Mn2+ + H2O2 → Mn4+ + 2OH-
4.Reducing action in basic medium
I2 + H2O2 + 2OH- → 2I- + 2H2O + O2
2MnO4- + 3H2O2 → 2MnO2 + 3O2 + 2H2O + 2OH-