Editing Oxide (section)

===Reduction===
{{see also|Carbothermic reduction}}
Reduction of metal oxide to the metal is practiced on a large scale in the production of some metals.  Many metal oxides convert to metals simply by heating ([[thermal decomposition]]). For example, [[silver oxide]] decomposes at 200&nbsp;°C:<ref>{{Cite web|url=http://chemister.ru/Database/properties-en.php?dbid=1&id=4098|title = Silver oxide}}</ref>
:<chem> 2 Ag2O -> 4 Ag + O2</chem>
Most often, however, metal oxides are reduced by a chemical reagent.  A common and cheap reducing agent is carbon in the form of [[coke (fuel)|coke]].  The most prominent example is that of [[Iron#Industrial production|iron ore smelting]]. Many reactions are involved, but the simplified equation is usually shown as:<ref name=Greenwood/>
: <chem>2 Fe2O3 + 3 C -> 4 Fe + 3 CO2</chem>

Some [[metal oxide]]s dissolve in the presence of reducing agents, which can include organic compounds.  Reductive dissolution of [[Ferric Oxide|ferric oxides]] is integral to [[geochemical]] phenomena such as the [[iron cycle]].<ref name="CornellSchwertmann2003-323">{{cite book|title=The Iron Oxides: Structure, Properties, Reactions, Occurrences and Uses, Second Edition|last1=Cornell|first1=R. M.|last2=Schwertmann|first2=U.|year=2003|page=323|doi=10.1002/3527602097|isbn=978-3-527-30274-1}}</ref>