What is a redox reaction?

A redox reaction is a chemical process where oxidation and reduction occur simultaneously.

In more detail, redox reactions, short for reduction-oxidation reactions, are fundamental types of chemical reactions that occur in various scientific fields, including chemistry, biology, and physics. The term 'redox' comes from two concepts: reduction and oxidation. These two processes always occur together, hence the term 'redox reaction'.

Oxidation refers to the loss of electrons during a reaction by a molecule, atom or ion. On the other hand, reduction describes the gain of electrons by a molecule, atom or ion. In simpler terms, if a substance is oxidised, it loses electrons, and if it is reduced, it gains electrons.

An easy way to remember this is by using the acronym OIL RIG, which stands for 'Oxidation Is Loss, Reduction Is Gain'. This refers to the movement of electrons during the reaction.

In a redox reaction, the substance that loses electrons (undergoes oxidation) is known as the reducing agent, because it 'donates' electrons and reduces the other substance. Conversely, the substance that gains electrons (undergoes reduction) is called the oxidising agent, as it 'accepts' electrons and oxidises the other substance.

Redox reactions are essential in numerous natural phenomena and technological processes. For instance, they are involved in the process of respiration in our bodies, photosynthesis in plants, the rusting of iron, and the operation of batteries. Understanding redox reactions is crucial for mastering many aspects of chemistry.