Question

Hydrogen peroxide acts both as an oxidising and as a reducing agent in alkaline solution towards certain first row transition metal ions. Illustrate both these properties of H₂O₂ using chemical equations.

Answer 1

Hydrogen peroxide is an hydride of oxygen with formula H2O2.It has an ability to act as oxidising as well as reducing agent both in acidic as well as in basic medium.

Oxidising Nature-

1. It oxidised black lead sulphide to white lead sulphate.

.PbS + 4H2O2 -------------> PbSO4 + 4H2O

2.Oxidises nitrites to nitrates.

NO2- + H2O2 -----------------> NO3- + H2O

Reducing Nature-

1.Reduces moist silver oxide to sliver.

H2O2 + Ag2O ----------------> Ag + H2O + O2

2.Reduecs chlorine to hydrogen chloride

Cl2 + H2O2 --------------> 2HCl + O2