What is electrolysis and how does it work?

Electrolysis is a process that uses an electric current to drive a non-spontaneous chemical reaction.

Electrolysis is a fascinating aspect of chemistry that involves the use of electricity to bring about a chemical change. This process is typically carried out in a setup known as an electrolytic cell, which consists of two electrodes (an anode and a cathode) submerged in an electrolyte. The electrolyte is a substance that contains free ions and can be either a molten ionic compound or an aqueous solution of some salts.

The electric current is supplied by a direct current (DC) power source, such as a battery. When the power source is connected, it creates a flow of electrons. These electrons are taken up by the positive ions (cations) at the cathode, causing a reduction reaction. Simultaneously, the negative ions (anions) move towards the anode, where they lose electrons in an oxidation reaction. This movement of ions constitutes the electric current.

The overall process is a redox reaction, where one substance is reduced (gains electrons) and another is oxidised (loses electrons). The substances that undergo these changes are often different elements, which can be extracted or synthesised through this process. For example, electrolysis is used in the extraction of aluminium from its ore, and in the electroplating of metals.

It's important to remember that electrolysis only occurs in non-spontaneous reactions, which are reactions that wouldn't occur without the input of energy. In this case, the energy is provided by the electric current. The amount of substance produced at each electrode during electrolysis is directly proportional to the amount of electricity passed through the electrolyte, a concept known as Faraday's First Law of Electrolysis.

In summary, electrolysis is a powerful tool in chemistry, allowing us to drive reactions that wouldn't otherwise occur, and enabling the extraction and synthesis of various elements.