Home > Encyclopedia of Science > Oxidation-Reduction Reaction

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• Redox and electron exchanges

The term oxidation-reduction reaction actually refers to two chemical reactions that always occur at the same time: oxidation and reduction. Oxidation-reduction reactions are also referred to more simply as redox reactions. Oxidation, reduction, and redox reactions can all be defined in two ways.

The simpler definitions refer to reactions involving some form of oxygen. As an example, pure iron can be produced from iron oxide in a blast furnace by the following reaction:

3 C + 2 Fe₂O₃ → 4 Fe + 3 CO₂

In this reaction, iron oxide (Fe₂O₃) gives away its oxygen to carbon (C). In chemical terms, the carbon is said to be oxidized because it has gained oxygen. At the same time, the iron oxide is said to be reduced because it has lost...