Editing Redox (section)

===Corrosion and rusting===
[[File:Rust screw.jpg|thumb|right|Oxides, such as [[iron(III) oxide]] or [[rust]], which consists of hydrated [[iron(III) oxide]]s Fe<sub>2</sub>O<sub>3</sub>·''n''H<sub>2</sub>O and [[iron(III) oxide-hydroxide]] (FeO(OH), Fe(OH)<sub>3</sub>), form when oxygen combines with other elements.]]
[[File:PyOx.JPG|thumb|Iron rusting in [[pyrite]] cubes]]
* The term [[corrosion]] refers to the electrochemical oxidation of metals in reaction with an oxidant such as oxygen. [[Rust]]ing, the formation of [[iron oxide]]s, is a well-known example of electrochemical corrosion: it forms as a result of the oxidation of [[iron]] metal. Common rust often refers to [[iron(III) oxide]], formed in the following chemical reaction:
::{{chem2|4 Fe + 3 O2 -> 2 Fe2O3}}
* The oxidation of iron(II) to iron(III) by [[hydrogen peroxide]] in the presence of an [[acid]]:
::{{chem2|Fe(2+) -> Fe(3+) + e(-)}}
::{{chem2|H2O2 + 2 e(-) -> 2 OH(-)}}
:Here the overall equation involves adding the reduction equation to twice the oxidation equation, so that the electrons cancel:
::{{chem2|2 Fe(2+) + H2O2 + 2 H(+) -> 2 Fe(3+) + 2 H2O}}