Q.State Faraday's laws of electrolysis.

Chemical Effects of Electric Current and Electrolysis

When an electric current passes through a conducting liquid (an electrolyte), it does more than heat it — it drives a chemical decomposition. This is the chemical effect of current, and the process is called electrolysis.

What happens

In an electrolyte the current is carried by ions, not free electrons. Positive ions (cations) drift to the negative electrode (cathode) and negative ions (anions) to the positive electrode (anode), where they gain or lose electrons and are deposited or liberated. Electrical energy is thus converted into chemical change.

Faraday's laws of electrolysis

First law: the mass $m$ liberated at an electrode is proportional to the charge $q$ passed:

where $I$ is the current, $t$ the time, and $Z$ the electrochemical equivalent of the substance (mass deposited per unit charge).

Second law: for the same charge, the masses of different substances liberated are proportional to their chemical equivalent weights $E$. The two laws combine through the Faraday constant $F \approx 96500\ \text{C/mol}$, since $Z = E/F$.

Applications …