Electrolysis of molten salts

Electrolytes are ionic compounds that are:

  • in the molten state (heated so they become liquids), or
  • dissolved in water

Under these conditions, the ions in electrolytes are free to move within the liquid or solution.

Electrolysis is a process in which electrical energy, from a direct current (dc) supply, breaks down electrolytes. The free moving ions in electrolytes are attracted to the oppositely charged electrodes which connect to the dc supply.

Electrodes and ions

The negatively charged electrode is called thecathode. Positively charged ions move towards the cathode.

The positively charged electrode is called the anode. Negatively charged ions move towards the anode.

Graphite electrodes are inert electrodes because they do not take part in the electrolysis reactions. Instead, they provide a surface on which these reactions can happen.

Two electrodes connected to a cell. The negative electrode attracts positive ions and the positive electrode attracts negative ions.Ions move towards the oppositely charged electrode.