Chloride is obtained by the electrolysis of brine solution (conc. NaCl solution). Chlorine is liberated at the anode the sodium metal is liberated at the cathode and reacts with water to form NaOH and H2 At anode oxidation takes place: Cl−→Cl+e− Cl+Cl→Cl2 At cathode reduction takes place: Na++e−→Na 2Na+2H2O→2NaOH+H2 Therefore, extraction of chlorine from brine solution is based on oxidation.