The removal of chloride ions and hydrogen ions leaves sodium ions and hydroxide ions in the solution. In another method which uses the Kellner-Solvay cell, saturated sodium chloride solution is electrolysed between a carbon anode and a flowing mercury cathode. Sodium is liberated at the cathode and dissolves in the mercury. Chlorine is liberated at the anode. If the mercury amalgam is then treated with water, sodium hydroxide solution is produced.
Chlorine is used to disinfect municipal water supplies and water in swimming pools.
It is used to manufacture household bleaches and disinfectants. Sodium hydroxide is used in the manufacture of synthetic fibres, soaps and detergents.