(i) Electrolytic process: When a solution of brine (NaCl) is electrolysed, Na+ and Cl– ions are formed. Na+ ion reacts with OH– ions of water and forms sodium hydroxide. Hydrogen and chlorine are liberated as gases.
(ii) Deacon’s process: In this process, a mixture of air and hydrochloric acid is passed up a chamber containing a number of shelves, pumice stones soaked in cuprous chloride are placed. Hot gases at about 723 K are passed through a jacket that surrounds the chamber.
The chlorine obtained by this method is dilute and is employed for the manufacture of bleaching powder. The catalysed reaction is given below,
