Electrolysis of Water
To electrolyze water, a dilute aqueous NaOH solution is used as an electrolyte and a carbon or platinum rod is used as an electrode. When water is electrolyzed, hydrogen gas is generated at the (-)pole and oxygen gas is generated at the (+)pole. The reaction formula at the each electrode can be expressed as follows.
(＋)pole: 2OH- → H2O ＋ 1/2 O2 ＋ 2e
(－)pole: 2H2O ＋ 2e → H2 ＋ 2OH-