The process of chemical decomposition of the electrolyte by passing electricity through its molten or dissolved state is called electrolysis. When an electric current passes through the solution, the ions respond to the applied potential difference, and they direct their movement toward the oppositely charged electrodes. An electrode is a solid electric conductor through which a current enters or leaves the electrolytic cell. There are two types of electrodes, depending on the flow of current through them. These two types of electrodes are:- Cathode & Anode.

Oxidation (loss of electrons) at the anode and reduction (gain of electrons) at the cathode lead to the formation of products at the electrodes, i.e., the cation moves towards the negatively charged electrode. In contrast, anions move toward the positively charged electrode, respectively. Michael Faraday was the first scientist to describe the quantitative aspects of electrolysis. Faraday’s first law of electrolysis states that “The amount of chemical reaction which occurs at any electrode during electrolysis by a current is proportional to the quantity of electricity passed through the electrolyte (solution or melt).” The amount of product formed at the electrode depends on the number of electrons, which depends on the quantity of electricity flowing through the electrolytic cell.

Charge on 1 electron = 1.602 × 10^-19C.
Charge on 1 mole of electrons = 1.602 × 10^-19× 6.02 × 10 ²³.
This is equal to the Faraday constant, denoted by F = 96488 C mol^-1 or ≃ 96500 C mol^-1.

Charge on n moles of electrons (Q) is
Q = nF m ∝ Q m ∝ I ×t = Z ×I×t Here, Q = quantity of electricity I = current in ampere (1 ampere) t = time in seconds (1 second ) Z = constant of proportionality F = Faraday constant.

In this experiment, the value of Faraday is determined by measuring the amount of charge required to reduce 1 mol of H⁺ ions, regarding the following reaction.
2H⁺_(aq) + 2e^- → H_2(g) or 1H⁺_(aq) + 1e^- → 1/2H_2(g).

The experimental value for faraday’s number can be determined through electrolysis of a copper wire. A coulometer (a standard electrolytic cell) determines the quantity of electricity passed from the amount of metal deposited or consumed. However, coulometers are not in use anymore, constant current (I) sources are available, and the quantity of electricity Q, passed is given by:-
Q = It

Here, Q is in Columbus when I is in ampere, and t is in seconds.
1C = 1A × 1s
We can measure the charge on the electron in coulombs, and it is equal to 1.60 × 10-19 C.

2H⁺_(aq) + 2e^- → H_2(g) or 1H⁺_(aq) + 1e^- → 1/2H_2(g).

The above equation represents that 1 hydrogen ion is reduced for every electron passed through the solution, and that one molecule of H₂ is produced for every 2 electrons. The charge passed through the electrolytic cell during electrolysis equals the product of current in amperes and time in seconds. The product of electrolysis depends on the following factors:

1. Nature of the materials being electrolysed.
2. Types of electrodes being used.
3. Kinetic barrier and overvoltage.

(a). Cathodic reactions.
(b). Anodic Reactions.
(c). Unexpected products because of overvoltage.