Electroplating (Cambridge (CIE) O Level Chemistry): Revision Note

Electroplating

• Electroplating is a process where the surface of one metal is coated with a layer of a different metal

• The anode is made from the pure metal you want to coat your object with

• The cathode is the object to be electroplated

• The electrolyte is an aqueous solution of a soluble salt of the pure metal at the anode

• Example: coating a strip of iron metal with tin:

A piece of iron being electroplated with tin. The electrolyte is tin(II) chloride, a water-soluble salt of tin

• At the anode: Tin atoms lose electrons to form tin ions in solution

• At the cathode: Tin ions gain electrons to form tin atoms which deposit on the strip of iron metal, coating it with a layer of tin

Uses of electroplating

• Electroplating is done to make metals more resistant to corrosion or damage

  • e.g, chromium and nickel plating

• It is also done to improve the appearance of metals,

  • e.g. coating cutlery and jewellery with silver