Uses Of
electrolysis
E lectrolysis refers to the process by
which a substance is decomposed or chemically changed by the passage of an electric current through it. The substance through which the current is passed, is known as the electrolyte. It may be molten in nature or aqueous. Electrolytes contain ions, which when mobile, allow for the free flow of electricity. Electrolysis is carried out via what is known as an“ electrolytic cell”( Figure 1). It comprises a power source, connected( via wires) to two electrodes( materials capable of conducting electricity), which are placed into the electrolyte. The electrode connected to the positive terminal of the power supply is called the“ anode”. The electrode connected to the negative terminal of the power supply is called the“ cathode”.
During electrolysis, the anions( negative ions) move towards the anode. Here, they lose electrons i. e. oxidation occurs. The cations( positive ions) move towards the cathode. Here, they gain electrons i. e. reduction occurs.
Electrolysis may be used in a number of applications. These include:--
Metal extraction Electroplating
Metal Extraction Metals that are higher
Figure 1: The Electrolytic Cell
than zinc in the electrochemical series are extracted using electrolysis. These very reactive metals cannot be extracted like other metals by methods such as reduction with carbon. They are obtained by electrolyzing a molten ionic compound of metal.
E. g.
Extraction Of Aluminium