ELECTROLYTE ANODE Product CATHODE Product Na 2 SO 4 ( aq ) with Pt electrode

When a dilute aqueous solution of electrolyte Na 2 SO 4 Is electrolysed using platinum electrode the following reaction takes place: Na 2 SO 4 ( aq ) ⇌ 2 Na + + S O 4 2 - In Na + and H + , H + Will reduce first because it has higher reduction potential than that of Na + . 2 Na + + 2 e - → 2 Na 2 Na + 2 H 2 O → 2 NaOH + H 2 ↑ In S O 4 2 - and OH - , OH - Will oxidise first because it has lower reduction potential than that of S O 4 2 - . S O 4 2 - + H 2 O → H 2 SO 4 + O + 2 e - O + O → O 2 So, at the cathode H 2 Will produce and at the anode O 2 Will be produced.

ELECTROLYTE ANODE Product CATHODE Product NaNO 3 ( aq ) with Pt electrode

Aqueous solution of sodium nitrate can be ionised as follows NaNO 3 → Na + + NO 3 - H 2 O → H + + OH - The competitive ions can be discharge based on its discharge potential. Ion which is having less discharge-potential will be deposited in preferential to other ions. Discharge potential: Na + < H + OH - < NO 3 - Hence, at anode: 4 OH - → 2 H 2 O + O 2 + 4 e - At cathode: 4 Na + + 4 e - → 4 Na

ELECTROLYTE ANODE Product CATHODE Product AgNO 3 (aq) with Pt electrode

Silver nitrate aqueous solution can be dissociated as follows: AgNO 3 → Ag + + NO 3 - At cathode: Silver ions have lowest discharge-potential than hydrogen ions, hence silver ions deposited at cathode. 4 Ag + + 4 e - → 4 Ag At Anode: Hydroxide ions are preferentially deposited over nitrate ions since their lowest discharge potential. 4 OH - → 2 H 2 O + O 2 + 4 e -

ELECTROLYTE ANODE Product CATHODE Product CuSO 4 ( aq ) with Inert electrode

The electrolyte CuSO 4 dissociates as Cu 2 + and S O 4 2 - along with H + and OH - ions in the aqueous solution. At cathode (reduction): As Cu 2 + has higher reduction potential than H + , it gets preferentially reduced. 2 Cu 2 + + 4 e - → 2 Cu At anode (oxidation): As OH - has higher oxidation potential than S O 4 2 - , it gets preferentially oxidised. 4 OH - → 2 H 2 O + O 2 + 4 e - Hence, Cu at the cathode and O 2 at the anode are produced by electrolysis of aqueous CuSO 4 with inert electrodes.