oxidation and reduction definition of oxidation and reduction in the Free Online Encyclopedia.

oxidation and reduction, complementary chemical reactions characterized by the loss or gain, respectively, of one or more electrons by an atom or molecule. Originally the term oxidation was used to refer to a reaction in which oxygen combined with an element or compound, e.g., the reaction of magnesium with oxygen to form magnesium oxide or the combination of carbon monoxide with oxygen to form carbon dioxide. Similarly, reduction referred to a decrease in the amount of oxygen in a substance or its complete removal, e.g., the reaction of cupric oxide and hydrogen to form copper and water.

When an atom or molecule combines with oxygen, it tends to give up electrons to the oxygen in forming a chemical bond chemical bond, mechanism whereby atoms combine to form molecules. There is a chemical bond between two atoms or groups of atoms when the forces acting between them are strong enough to lead to the formation of an aggregate with sufficient stability to be regarded as
..... Click the link for more information. . Similarly, when it loses oxygen, it tends to gain electrons. Such changes are now described in terms of changes in the oxidation number, or oxidation state, of the atom or molecule (see valence valence, combining capacity of an atom expressed as the number of single bonds the atom can form or the number of electrons an element gives up or accepts when reacting to form a compound.
..... Click the link for more information. ). Thus oxidation has come to be defined as a loss of electrons or an increase in oxidation number, while reduction is defined as a gain of electrons or a decrease in oxidation number, whether or not oxygen itself is actually involved in the reaction.

In the formation of magnesium oxide from magnesium and oxygen, the magnesium atoms have lost two electrons, or the oxidation number has increased from zero to +2. This is also true when magnesium reacts with chlorine to form magnesium chloride. In solution, ferrous iron (oxidation number +2) may be oxidized to ferric iron (oxidation number +3) by the loss of an electron. In the reduction of cupric oxide the oxidation number of copper has changed from +2 to zero by the gain of two electrons. The two processes, oxidation and reduction, occur simultaneously and in chemically equivalent quantities. In the formation of magnesium chloride, for every magnesium atom oxidized by a loss of two electrons, two chlorine atoms are reduced by a gain of one electron each.

Oxidation-reduction reactions, called also redox reactions, are most simply balanced in the form of chemical equations by arranging the quantities of the substances involved so that the number of electrons lost by one substance is equaled by the number gained by another substance. In such reactions, the substance losing electrons (undergoing oxidation) is said to be an electron donor, or reductant, since its lost electrons are given to and reduce the other substance. Conversely, the substance that is gaining electrons (undergoing reduction) is said to be an electron acceptor, or oxidant.

Common reductants (substances readily oxidized) are the active metals, hydrogen, hydrogen sulfide, carbon, carbon monoxide, and sulfurous acid. Common oxidants (substances readily reduced) include the halogens (especially fluorine and chlorine), oxygen, ozone, potassium permanganate, potassium dichromate, nitric acid, and concentrated sulfuric acid. Some substances are capable of acting either as reductants or as oxidants, e.g., hydrogen peroxide and nitrous acid.

The corrosion corrosion, atmospheric oxidation of metals (see oxidation and reduction). By far the most important form of corrosion is the rusting of iron. Rusting is essentially a process of oxidation in which iron combines with water and oxygen to form rust, the reddish-brown
..... Click the link for more information. of metals is a naturally occurring redox reaction. Industrially, many redox reactions are of great importance: combustion combustion, rapid chemical reaction of two or more substances with a characteristic liberation of heat and light; it is commonly called burning. The burning of a fuel (e.g., wood, coal, oil, or natural gas) in air is a familiar example of combustion.
..... Click the link for more information. of fuels; electrolysis electrolysis , passage of an electric current through a conducting solution or molten salt that is decomposed in the process. The Electrolytic Process

..... Click the link for more information. (oxidation occurs at the anode and reduction at the cathode); and metallurgical processes in which free metals are obtained from their ores.

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No references found			Some of his topics are solutions and simple phase relations, the chemistry of igneous rocks, stable isotope geochemistry, oxidation and reduction, and atmospheric chemistry. Essentials of geochemistry, 2d ed by SciTech Book News s main defense against free radicals as they work against the substances that create oxidants and the reactive substances that result from oxidation and reduction Antioxidants neutralize free radicals by supplying the missing electron so that the molecule may be stabilized Antioxidants are the body? Reduce the Signs of Aging with Antioxidants by Darrell Miller / Food/cooking/nutrition community However, the jury is still out on how effective screw caps are at addressing other issues such as random oxidation and reduction. Letters by Cheers			Oxford Oxford and Asquith, Herbert Henry Asquith, 1st earl of oxford cloth Oxford County Oxford English Dictionary Oxford English Dictionary, The Oxford Group Oxford movement Oxford sheep Oxford Slough National Wildlife Refuge Oxford University Oxford, Edward de Vere, 17th earl Oxford, Edward de Vere, 17th earl of Oxford, Provisions Oxford, Provisions of Oxford, Robert Harley, 1st earl of Oxford, University Oxfordian Oxfordian Stage Oxfordshire oxidant oxidase Oxidases oxidate Oxidation oxidation and reduction Oxidation Number Oxidation of Metals oxidation pond oxidation potential Oxidation Resistance oxidation state Oxidation Zone of Mineral Deposits Oxidation, Biological oxidation-reduction oxidation-reduction indicator Oxidation-Reduction Potential Oxidation-Reduction Reaction Oxidation-Reduction Reaction in Organisms Oxidative Phosphorylation Oxide Oxide Coating oxide fuel reactor oxide isolation oxide mineral oxide nuclear fuel oxide passivation oxide-coated cathode Oxides, Natural Oxidimetry oxidite			oxidant oxidant Oxidant stress Oxidant stress Oxidants Oxidants Oxidants oxidase oxidase oxidase Oxidase test Oxidase test Oxidase test Oxidases Oxidases Oxidases oxidasic oxidasic oxidasic oxidate oxidate Oxidating Oxidating Oxidating oxidation oxidation oxidation Oxidation (chemistry) Oxidation (chemistry) Oxidation (chemistry) oxidation and reduction Oxidation base Oxidation base Oxidation base Oxidation base Oxidation Enhanced Diffusion Oxidation half reaction Oxidation half reaction Oxidation half reaction Oxidation Induced Stacking Fault Oxidation Induction Temperature Oxidation Induction Time Oxidation Is Loss Reduction Is Gain oxidation number oxidation number oxidation number oxidation number Oxidation numbers Oxidation numbers Oxidation of Metals Oxidation Phenomena in Severe Accidents oxidation pond oxidation potential Oxidation process Oxidation process Oxidation process Oxidation reaction Oxidation reaction Oxidation reaction Oxidation reduction Oxidation reduction