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