Question

In a class room, the teacher has explained the quantitative aspects of electrolysis by stating the Faraday’s laws of electrolysis.

(a) State the Faraday’s laws of electrolysis. 

(b) Explain the term electrochemical equivalent. 

(c) Calculate the quantity of electricity required to deposit 0.09 g of Aluminium during the following electrode reaction: 

Al³⁺ + 3e → Al (Atomic mass of Al = 27)

Answer 1

(a) First law : The amount of a substance which is deposited or liberated at any electrode during ectrolysis is directly proportional to the quantity of electricity owing through the electrolyte.

Second law: If the same quantity of electricity is passed through dierent electrolytes the amount of substances formed is directly proportional to their chemical equivalent weights. 

(b) It is the quantity of a substance formed when one-ampere current is passed through an electrolyte for one second. 

(c) Quantity of electricity required to deposit 27 g of 

Al = 3F = 3 x 96500 C = 289500 C 

∴ the quantity of electricity required to deposit 0.09