Oxidation–Reduction Reactions

Oxidation causes an increase in ionic charge, and reduction causes a decrease. Oxidation of a chemical involves the loss of electrons. Reduction is the reverse, a gain in electrons. The oxidized substance is the electron donor and the reduced substance is the electron acceptor. Organic compounds can be oxidized to carbon dioxide and water. Reduction processes may be used to convert toxic organics to a much less toxic form, or to an easily biodegraded form. All biological reactions are paired oxidation-reduction reactions. Oxidation numbers are hypothetical numbers assigned to an individual atom or ion and to groups of atoms or ions. Oxidation numbers can be positive, negative, or zero. Chlorine is the most widely used and important oxidizing agent. Fenton's reagent, a solution of hydrogen peroxide and an iron catalyst, is one of the most effective methods for the oxidation of organic pollutants.