The process of decomposition and then deposition of an electrolyte by the passage of  electric current is called electrolysis. During this process electrical energy is converted  into chemical energy. The weight of the substance deposited at the electrode is directly  proportional to quantity of the electricity entered into electrolyte.

$W\alpha Q$

$W=e.Q$

Take 1 Faraday = 96500 coulombs
W = Weight of the substance deposited of the electrode
Q = Quantity of electricity
e  = Electro chemical equivalent