Electrolysis of brine

Electrolysis of brine :

Electrolysis of brine gives hydrogen gas at the cathode and chlorine gas at the anode. Sodium hydroxide remains dissolved in the solution.

The half equations are :-

Electrolysis of brine

At the cathode: Hydrogen ions gain electrons (reduction) to form hydrogen atoms. The hydrogen atoms combine to form molecules of hydrogen gas.

2H+ + 2e-  H2

At the anode: Chloride ions lose electrons (oxidation) to form chlorine atoms. The chlorine atoms combine to form molecules of chlorine gas.

 2Cl- - 2e-  Cl2

The overall reaction is

 2NaCl(aq) + 2H2O(l)  2Na+(aq) + 2OH-(aq) + Cl2(g)+ H2(g)