Question

When we do electrolysis we give dilute sulphuric acid ( CONTAINS HYDROGEN ) in the water.

When the electricity is passed, the hydrogen and oxygen are collected.

The hydrogen which is collected is of Sulphuric acid or of the water ? Why ?

Answer 1

Sulphuric acid acts as a catalyst. It increases the conductivity of water and thus increases the rate of electrolysis. The chemical composition of the reactant or products remains same.Therefore, hydrogen is collected due to breaking up of water molecules into H⁺ and OH ^– ions.

The reaction that takes place during the process can be shown as:-

2H ₂ O → 2H ₂ + O ₂

At cathode:

2 H ⁺ _(aq) +2e ^- → H ₂

At anode:-

OH ^- _(aq) → OH + e ^-

4 OH → 2H ₂ O + O ₂