The chlor-alkali process is an industrial method for the electrolysis of sodium chloride (NaCl) solutions. It is called the chlor-alkali process because it involves the production of chlorine (chlor) and sodium hydroxide (alkali) through electrolysis. The process can be summarized by the following equation:
$$ 2NaCl(aq) + 2H_2O(l) \rightarrow 2NaOH(aq) + Cl_2(g) + H_2(g) $$
In this process, an electric current is passed through an aqueous solution of sodium chloride (brine). As a result, sodium hydroxide, chlorine gas, and hydrogen gas are produced. The chlor-alkali process has been in use since the 19th century and is a primary industry in the United States, Western Europe, and Japan. It has become the principal source of chlorine during the 20th century.
