Faraday’s laws of electrolysis describe the relationship between the amount of material deposited or produced during electrolysis and the quantity of electricity that passes through the electrolytic cell. These laws were developed by the English scientist Michael Faraday in the early 19th century.
The first law of electrolysis states that the amount of material deposited or produced at an electrode during electrolysis is proportional to the amount of electricity that passes through the cell. This means that the amount of material deposited on an electrode is directly proportional to the quantity of electric charge that passes through the cell. The law can be expressed mathematically as:
m = zFQ
where m is the mass of material deposited, z is the number of electrons transferred per ion during the electrolysis reaction (also known as the electrochemical equivalent), F is the Faraday constant (equal to 96,485 coulombs per mole of electrons), and Q is the quantity of electric charge that passes through the cell.
The second law of electrolysis states that the amount of material deposited or produced during electrolysis is proportional to the chemical equivalent weight of the material. This means that the amount of material deposited on an electrode is directly proportional to its atomic weight divided by its valence. The law can be expressed mathematically as:
m1/m2 = E1/E2
where m1 and m2 are the masses of two different materials deposited during electrolysis, and E1 and E2 are their respective chemical equivalent weights.
Faraday’s laws of electrolysis are important in understanding and predicting the outcome of electrochemical reactions, and they have many practical applications in various fields, including electroplating, metal refining, and battery technology.