Oksüdoreduktsioon

Oksüdoreduktsioon, often shortened to redoks, is a type of chemical reaction that involves a transfer of electrons between two species. These reactions are fundamental to many chemical processes, including combustion, corrosion, respiration, and photosynthesis. The term "redoks" is a portmanteau derived from "reduction" and "oxidation."

Oxidation refers to the loss of electrons by a molecule, atom, or ion. This loss typically results in an increase in the oxidation state of the species. Conversely, reduction refers to the gain of electrons by a molecule, atom, or ion, leading to a decrease in its oxidation state. In any redoks reaction, oxidation and reduction occur simultaneously; one species is oxidized while another is reduced.

The species that loses electrons and is oxidized is called the reducing agent, as it causes the other species to be reduced. The species that gains electrons and is reduced is called the oxidizing agent, as it causes the other species to be oxidized. Identifying the oxidation states of the atoms involved is crucial for understanding and balancing redoks reactions. Oxidation states are hypothetical charges assigned to atoms in a molecule or ion, assuming that all bonds are ionic.

Redoks reactions are ubiquitous in nature and technology. For example, the rusting of iron is an oxidation process where iron loses electrons to oxygen. The energy released in cellular respiration is a result of a series of redoks reactions that transfer electrons from glucose to oxygen. Batteries and fuel cells also operate based on controlled redoks reactions that generate electrical energy.