Question

In electrolysis of water name the gases liberated at cathode and anode.

Answer 1

Electrolysis of water:

1. The electrolysis of water results in the breakdown of water into Oxygen and Hydrogen gas. An electric current is passed through the solution to achieve this.
2. Electrolysis is represented through a decomposition reaction. This is because an electric current causes water to split into its essential elements, Hydrogen, and Oxygen.
3. Reaction for electrolysis of water is as follows $2\underset{\mathrm{water}}{{\mathrm{H}}_2\mathrm{O}\left(\mathrm{l}\right)}\rightleftharpoons \underset{\mathrm{Oxygen}\mathrm{gas}}{{\mathrm{O}}_2\left(\mathrm{g}\right)}+\underset{\mathrm{hydrogen}\mathrm{gas}}{2{\mathrm{H}}_2\left(\mathrm{g}\right)}$
4. At the anode oxidation takes place i.e. loss of electron $\underset{\mathrm{water}}{2{\mathrm{H}}_2\mathrm{O}\left(\mathrm{l}\right)}\to \underset{\mathrm{Oxygen}\mathrm{gas}}{{\mathrm{O}}_2\left(\mathrm{g}\right)}+4{\mathrm{H}}^{+}\left(\mathrm{aq}\right)+4{\mathrm{e}}^{-}$
5. At cathode reduction occur i.e. gain of electron takes place $\underset{\mathrm{water}}{2{\mathrm{H}}_2\mathrm{O}\left(\mathrm{l}\right)}+2{\mathrm{e}}^{-}\to \underset{\mathrm{Hydrogen}\mathrm{gas}}{{\mathrm{H}}_2\left(\mathrm{g}\right)}+2{\mathrm{OH}}^{-}$
6. Hence, in the electrolysis of water hydrogen and gas are liberated.

Therefore, in the electrolysis of water hydrogen gas is liberated at the cathode, and oxygen gas is liberated at the anode.