Write the electrode reactions involved in the electrolysis of aqueous CuCl2 using graphite electrodes?
Answers
Answer:
An aqueous solution of AgNO
3
with silver electrodes.
At cathode: Silver ions have lower discharge potential than hydrogen ions. Hence, silver ions will be deposited in preference to hydrogen ions.
At anode: Silver anode will dissolve to form silver ions in the solution.
Ag→Ag
+
+e
−
(ii) An aqueous solution of AgNO
3
with platinum electrodes.
At cathode: Silver ions have lower discharge potential than hydrogen ions. Hence, silver ions will be deposited in preference to hydrogen ions.
At anode: Hydroxide ions having lower discharge potential will be discharged in preference to nitrate ions. Hydroxide ions will decompose to give oxygen.
4OH
−
(aq)→2H
2
O(l)+O
2
(g)+4e
−
(iii) A dilute solution of H
2
SO
4
with platinum electrodes.
At cathode: 2H
+
+2e
−
→H
2
(g)
At anode: Hydroxide ions having lower discharge potential will be discharged in preference to sulphate ions. Hydroxide ions will decompose to give oxygen.
4OH
−
(aq)→2H
2
O(l)+O
2
(g)+4e
−
(iv) An aqueous solution of CuCl
2
with platinum electrodes
At cathode: Cupric ions will be reduced in preference to protons
Cu
2+
+2e
−
→Cu
At anode: Chloride ions will be oxidized in preference to hydroxide ions
2Cl
−
→Cl
2
+2e
−