Editing Redox (section)

{{short description|Chemical reaction with oxidation state changes}}
{{other uses}}
{{Use mdy dates|date=November 2020}}{{Use American English|date=November 2020}}

[[File:NaF.gif|upright=1.6|class=skin-invert-image|thumb|right|[[Sodium]] "gives" one outer electron to [[fluorine]], bonding them to form [[sodium fluoride]]. The sodium atom is oxidized, and fluorine is reduced.]]
[[File:16. Реакција меѓу силно оксидационо и редукционо средство.webm|thumb|right|upright=1.25|When a few drops of [[glycerol]] (mild reducing agent) are added to powdered [[potassium permanganate]] (strong oxidizing agent), a violent redox reaction accompanied by self-ignition starts.]]
{{redox_example.svg}}

'''Redox''' ({{IPAc-en|ˈ|r|ɛ|d|ɒ|k|s}} {{respell|RED|oks}}, {{IPAc-en|ˈ|r|iː|d|ɒ|k|s}} {{respell|REE|doks}}, '''reduction–oxidation'''<ref>{{Cite web|url=https://en.oxforddictionaries.com/definition/redox|title=redox – definition of redox in English {{!}} Oxford Dictionaries|website=Oxford Dictionaries {{!}} English|access-date=2017-05-15|archive-url=https://web.archive.org/web/20171001031248/https://en.oxforddictionaries.com/definition/redox|archive-date=2017-10-01|url-status=dead}}</ref> or '''oxidation–reduction'''<ref name=Petrucci2002>{{cite book |last1=Petrucci |first1=Ralph H. |last2=Harwood |first2=William S. |last3=Herring |first3=F. Geoffrey |title=General Chemistry |date=2002 |publisher=Prentice-Hall |isbn=0-13-014329-4 |edition=8th}}</ref>{{rp|150}}) is a type of [[chemical reaction]] in which the [[oxidation state]]s of the [[reactant]]s change.<ref>{{cite web|url=http://www.wiley.com/college/boyer/0470003790/reviews/redox/redox.htm|title=Redox Reactions|publisher=wiley.com|archive-url=https://web.archive.org/web/20120530081215/http://www.wiley.com/college/boyer/0470003790/reviews/redox/redox.htm|archive-date=2012-05-30|url-status=live|access-date=2012-05-09}}</ref> Oxidation is the loss of [[electron]]s 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.

There are two classes of redox reactions:
* [[Electron transfer|Electron-transfer]] – 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.
* Atom transfer – An atom transfers from one [[Substrate (chemistry)|substrate]] to another.  For example, in the [[rusting]] of [[iron]], the oxidation state of iron atoms increases as the iron converts to an [[oxide]], 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.<ref name="gale">{{cite encyclopedia | last =  Haustein  | first = Catherine Hinga | title = Oxidation-reduction reaction |encyclopedia=The Gale Encyclopedia of Science |edition=5th |editor1= K. Lee Lerner |editor2=Brenda Wilmoth Lerner | publisher = Gale Group | location = Farmington Hills, MI | year = 2014 | url = https://link.gale.com/apps/doc/CV2644031629/SCIC?u=dc_demo&sid=SCIC&xid=baa9fde9 }}</ref> In [[hydrogenation]], bonds like [[alkene|C=C]]  are reduced by [[Transfer hydrogenation|transfer of hydrogen atoms]].