In decomposition of sodium chloride on which rods do Cl2 and H2 get deposited
In the electrolysis of aqueous solution of sodium chloride (also called brine), hydrogen is formed at the cathode while chlorine gas is formed at the anode. Sodium hydroxide is formed near the cathode. Following is the chemical equation for the reaction
2NaCl (aq) + 2H2O (l) → 2NaOH (aq) + Cl2 (g) + H2 (g)