Oxidation involves increase in oxidation number and reduction involves decrease in oxidation number. 2I−+2H++H2
1
O
2⟶
1
I
2+2
+1
H
2
−2
O
2 In this reaction, H2O2 oxidises I−to I2 and itself gets reduced to H2O, so the reaction depicts oxidising nature of H2O2. While in other reactions H2O2 does not oxidise KlO4,I2 and Cl2.