Redox

<p>Redox  is a type of <a href="/facts/Chemical_reaction/GpqWlKrz">chemical reaction</a> in which the <a href="/facts/Oxidation_state/W53W6s6V">oxidation states</a> of the <a href="/facts/Reactant/c3GLInCu">reactants</a> change. Oxidation is the loss of <a href="/facts/Electron/L0KBo5cW">electrons</a> or an increase in the oxidation state, while reduction is the gain of electrons or a decrease in the oxidation state. The oxidation and reduction processes occur simultaneously in the chemical reaction.
</p><p>There are two classes of redox reactions:
</p>
<ul><li><a href="/facts/Electron_transfer/BIdASS9R">Electron-transfer</a> – Only one (usually) electron flows from the atom, ion, or molecule being oxidized to the atom, ion, or molecule that is reduced. This type of redox reaction is often discussed in terms of redox couples and electrode potentials.</li>
<li>Atom transfer – An atom transfers from one <a href="/facts/Substrate_(chemistry)/6MnaV19h">substrate</a> to another.  For example, in the <a href="/facts/Rusting/sajUmaz8">rusting</a> of <a href="/facts/Iron/QK1JYy8E">iron</a>, the oxidation state of iron atoms increases as the iron converts to an <a href="/facts/Oxide/DXtoVe1C">oxide</a>, and simultaneously, the oxidation state of oxygen decreases as it accepts electrons released by the iron. Although oxidation reactions are commonly associated with forming oxides, other chemical species can serve the same function. In <a href="/facts/Hydrogenation/l7EzNSA7">hydrogenation</a>, bonds like <a href="/facts/Alkene/RtYcS6kU">C=C</a>  are reduced by <a href="/facts/Transfer_hydrogenation/5IQkKatC">transfer of hydrogen atoms</a>.</li></ul>

Redox open-in-new

Redox