So far we have been discussing the process of conversion of chemical energy into electrical energy by means of electrochemical cell. In the reverse process, the passage of electricity through the electrolytes in their molten or dissolved state can cause chemical changes under suitable conditions. For example, the passage of electricity through the acidified water results in the formation of hydrogen and oxygen gases. The process of chemical decomposition of the electrolyte by he passage of electricity through its molten or dissolved state is called electrolysis.
ELECTROL YTIC CELL
The device in which the process of electrolysis is carried 1ut is called electrolytic cell. It consists of:
(i) Electrolytic tank, which is made of some nonconducting materials like glass, wood or bakelite.
(ii) Electrolyte in its dissolved state or molten state.
(iii) Source of electricity; an electrochemical cell or battery.
(iv) Two metallic rods, suspended in the electrolyte and connected to the battery through conducting wires. These rods are called electrodes. The electrode connected to the negative terminal of battery is called cathode while the other one which is connected to the positive terminal is called anode. The apparatus used to constitute electrolytic cell has been shown in Fig. 34.2.