Question

Draw a neat labelled diagram of electrolysis of water.

Answer 1

Electrolysis: Electrolysis is defined as the process by which ionic substances are decomposed into simpler substances when an electric current is passed through them.

Water electrolysis :

Electrolysis of water is the chemical reaction in which the decomposition of hydrogen and oxygen gases is carried by passing an electric current. The electrolysis of water is mainly carried out to yield pure hydrogen and oxygen gases. It involves passing an electric current through the water which results in the decomposition of water into hydrogen and oxygen.

Half reactions in the electrolysis of pure water :

At cathode : $2{\mathrm{H}}_2\mathrm{O}\left(\mathrm{l}\right)+2{\mathrm{e}}^{-}\to {\mathrm{H}}_2\left(\mathrm{g}\right)+2{\mathrm{OH}}^{-}$

At anode : $2{\mathrm{H}}_2\mathrm{O}\left(\mathrm{l}\right)\to {\mathrm{O}}_2\left(\mathrm{g}\right)+4{\mathrm{H}}^{+}+4{\mathrm{e}}^{-}$

The net reaction of electrolysis of water is given as:

$2{\mathrm{H}}_2\mathrm{O}\to 2{\mathrm{H}}_2\left(\mathrm{g}\right)+{\mathrm{O}}_2\left(\mathrm{g}\right)$