Electrolysis

Electrolysis is often used to give metal objects a decorative coating. This is known as electroplating.

Electrolysis happens when an electric current is passed through an ionic compound which has been melted or dissolved. Electrolysis has a wide range of uses including  :

electroplating, extraction of aluminium, production of chlorine , purification of copper .

This page helps you to understand and explain the various changes that can happen in electrolysis.

Explaining Electrolysis  

​A liquid substance containing ions which are mobile can conduct an electric current. When this happens chemical changes take place at the electrodes. Electrons are given off at the negative electrode ( cathode) and electrons are taken away from the positive electrode ( anode).

The ions ( which are mobile because they are molten or dissolved) will migrate as the electric field is applied.  The positive ions will migrate to the negative electrode and the negative ions migrate to the positive electrode.

Melting Sodium Chloride

 Electrolysis is used to extract reactive metal from their ores. Aluminium is a good example of this.