The process of deposition of metal at the surface of another metal is known as electroplating or metallic coating.
In this process, the object to be electroplated is cleaned with sand, washed with caustic soda solution and finally it is thoroughly washed with water.
The anode is made of metal, which is to be deposited like Sn, Zn, Ag, Cr, and Ni. The cathode is made up of the object that is to be electroplated like some sheet made up of iron. The electrolyte in this system is the salt of the metal being deposited. The electrolytic tank is made of cement, glass, or wood in which the anode and cathode are suspended. These electrodes are connected to a battery. When the current is passed, the metal from the anode dissolves in the solution and metallic ions migrate to the cathode and discharge or deposit on the cathode (object). As a result of this discharge, a thin layer of metal deposits on the object, which is then pulled out and cleaned.
The pure piece of silver strip acts as an anode immersed in a silver chloride solution. The cathode is a steel spoon. When the current is passed through the cell, the anode dissolves to produce Ag+2 ions that migrate toward the cathode. At the cathode, they are discharged and deposited on the spoon. The chemical reaction can be represented as
At anode:Ag → Ag+ + 1e
At cathode: Ag + 1e → Ag
