What is necessary for oxidation-reduction reactions to occur?

Oxidation-reduction reactions, commonly referred to as redox reactions, involve the transfer of electrons between two substances. A crucial component of these reactions is the presence of chemical oxidizers, which are substances that can accept electrons from other substances. The oxidizer is reduced in the process, meaning it gains electrons.

For example, in the familiar reaction of rusting, iron reacts with oxygen to form iron oxide. In this scenario, oxygen acts as the chemical oxidizer, accepting electrons from iron. Without an oxidizer present, the necessary electron transfer for the reaction would not occur, thus preventing the redox process from taking place.

While catalysts can accelerate reactions, they do not change the fundamental nature of oxidation-reduction processes. Similarly, high temperatures and pressure adjustments may influence reaction rates or equilibrium but are not strictly necessary for the occurrence of redox reactions themselves. The defining and essential component that allows these reactions to happen is the availability of a chemical oxidizer that facilitates the electron transfer.