(a) Electroplating an article with nickel :
- Electrolyte — Aqueous solution of Nickle Sulphate
- Cathode used — Cleaned article to be electroplated
- Anode used — Active electrode. Plate or block of nickle metal
- Electrode reaction at cathode — Ni2+ + 2e– ⟶ Ni [deposited]
- Electrode reaction at anode — Ni – 2e– ⟶ Ni2+
- Product at cathode — Nickel. (It is deposited on the article.)
Product at anode — Nil (Ni2+ ions formed)
(b) Electroplating a spoon with silver :
- Electrolyte — Sodium argentocyanide Na[Ag(CN)2]
- Cathode used — Cleaned article to be electroplated
- Anode used — Active electrode. Plate or block of Silver metal
- Electrode reaction at cathode — Ag1+ + 1e– ⟶ Ag [deposited]
- Electrode reaction at anode — Ag – 1e– ⟶ Ag1+
- Product at cathode — Silver. (It is deposited on the article.)
Product at anode — Nil (Ag1+ ions formed)
(c) Purification of impure copper :
- Electrolyte — Aqueous copper sulphate solution [acidified]
- Cathode used — Pure thin sheet of copper
- Anode used — Impure block of copper
- Electrode reaction at cathode — Cu2+ + 2e– ⟶ Cu [deposited]
- Electrode reaction at anode — Cu – 2e– ⟶ Cu2+ [cation]
- Product at cathode — Pure Copper. (It is deposited over thin sheet of pure Copper.)
Product at anode — Nil (Cu2+ ions formed)