Electroplating

Defined as the coating of an object with a thin layer of metal via electrolysis. It is also known as the deposition of a metal coating onto an object by putting a negative charge on it and putting it into a solution which contains a metal salt. The metal salt contains positively charged metal ions which are attracted to the negatively charged object and are reduced to a metal atom.

For instance, the electroplating of an object with copper, using copper(II) sulfate as the electrolyte, copper as the anode and the object to be electroplated as the cathode.

At the anode:
Copper metal is oxidised to form copper ions.
Equation: Cu(s) -> Cu2+(aq) + 2e-
The copper ions enter the solution.

At the cathode:
Copper(II) ions are reduced to form copper metal, which is deposited on the object. There is a net movement of copper from the anode to the cathode. Copper (II) sulphate solution remains unchanged.
Equation: Cu2+ (aq) + 2e- -> Cu (s)





Electroplating is very important and have many uses, for instance to protect the surfaces of other metals, like nickel plating of iron to prevent iron from being oxidised and rusting, to make objects attractive, like electroplating of silver and gold on brass, and to repair machine parts. Sometimes, specific metals like nickel are used to prevent rust, while silver is used for utensils and trophies/metals.