Chemistry
'Iron is electroplated with silver' —
(i) define the term in italics
(ii) state two reasons for electroplating
(ii) state why the iron is not placed at the anode and silver at the cathode during electroplating.
Electrolysis
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Answer
(i) Electroplating — It is the electrolytic process of deposition of a superior metal [i.e., nickle, silver, chromium, gold] on the surface of a baser metal or article [e.g., iron, copper, brass]
(ii) Reasons for electroplating:
- Prevents corrosion or rusting — of the base metal.
- Makes the article attractive and gives it an expensive appearance.
(iii) The article to be electroplated (i.e., iron) is always placed at the cathode because during electrolytic reaction the metal is always deposited at the cathode by gain of electrons.
The metal to be plated on the article (i.e., silver) is always made the anode because the metal anode continuously dissolves as ions in solution and is hence replaced periodically.
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