Question

Why small quantity of sulphuric acid is added to water for its electrolysis?

Answer 1

1. Electrolysis is the process of passage of electric current in a solution that dissociates into ions to conduct electricity.
2. Since pure water is a bad conductor of electricity, it does not have free electrons/ions for electrolysis.
3. On adding a little acid, the ${\mathrm{H}}_2\mathrm{O}$dissociate to form ${\mathrm{H}}^{+}\mathrm{and}{\mathrm{OH}}^{-}$ ions.

Hence acid is added to make it an electrolyte.