Oxoacid 3156262 202307150 2008-03-31T15:06:14Z 138.87.214.100 /* Note */ An '''oxoacid''' is an [[acid]] which contains [[oxygen]]. More specifically, it is an acid which: #contains oxygen; #contains at least one other [[Chemical element|element]]; #has at least one [[hydrogen]] atom bound to oxygen; and #forms an ion by the loss of one or more protons.{{ref|Boric}} The name '''oxyacid''' is sometimes used, although this is not recommended. Generally, oxoacids are simply [[polyatomic ions]] with a hydrogen [[cation]]. Under [[Lavoisier]]'s original [[Acid-base reaction theories|theory]], all acids contained oxygen, which was named from the [[Greek language|Greek]] οξυς (''oxys'') (acid, sharp) and γεινομαι (''geinomai'') (engender). It was later discovered that some acids, notably [[hydrochloric acid]], did not contain oxygen and so a distinction was made for those that did. Common oxoacids include: *Halogen oxoacids: [[Hypochlorous acid]]; [[Chlorous acid]]; [[Chloric acid]]; [[Perchloric acid]]; [[Perbromic acid]]; [[Metaperiodic acid]] *[[Sulfuric acid]] *[[Nitric acid]] *[[Phosphoric acid]] Common acids which are not oxoacids include: *[[Hydrochloric acid]] *[[Hydrofluoric acid]] *[[Hydrobromic acid]] *[[Hydroiodic acid]] Although [[carboxylic acid]]s fulfill the criteria above, they are not generally considered as oxoacids. All oxoacids have the acidic hydrogen bound to an oxygen atom, so bond strength (length) is not a factor as it is with binary nonmetal hydrides. Rather, the electronegativity of the central atom (E) and the number of O atoms determine oxoacid acidity. With the same central atom E, acid strength increases as the number of oxygen attached to E increases. With the same number of oxygens around E, acid strength increases with the electronegativity of E. == Note == #{{note|Boric}} This final criterion has the effect of excluding [[boric acid]] from the strict definition, as it forms its anion by addition of hydroxide rather than loss of a proton: B(OH)<sub>3</sub>&nbsp;+&nbsp;H<sub>2</sub>O&nbsp;{{unicode|&#8652;}} [B(OH)<sub>4</sub>]<sup>&minus;</sup>&nbsp;+&nbsp;H<sup>+</sup>. However, boric acid is usually considered to be an oxoacid nonetheless. ==See also== *[[Strong Acid]] *[[Weak Acid]] *[[Electronegativity]] ==External links== *[http://www.iupac.org/goldbook/O04374.pdf IUPAC definition of "oxoacid"] (from the "''Gold Book''") [[Category:Acids]] {{chem-stub}} [[et:Hapnikhapped]] [[es:Ácido oxácido]] [[fr:Oxoacide]] [[ko:산소산]] [[it:Ossiacidi]] [[ja:オキソ酸]] [[pt:Oxiácido]] [[zh:含氧酸]]