Editing Hydroxide (section)

===Other main-group elements===
{|class="wikitable" style="text-align:center"
|[[File:Phosphonic-acid-2D-dimensions-vector.svg|center|150px]]
|[[File:Phosphoric-acid-2D-dimensions.svg|center|180px]]
|[[File:Sulfuric-acid-2D-dimensions.svg|center|180px]]
|[[File:Telluric acid.svg|center|150px]]
|[[File:Ortho-Periodsäure.svg|center|150px]]
|[[File:Xenic acid.png|center|150px]]
|-
|[[Phosphorous acid]]
|[[Phosphoric acid]]
|[[Sulfuric acid]]
|[[Telluric acid]]
|[[Orthoperiodic acid]]
|[[Xenic acid]]
|}

In the higher oxidation states of the [[pnictogen]]s, [[chalcogen]]s, [[halogen]]s, and [[noble gas]]es there are oxoacids in which the central atom is attached to oxide ions and hydroxide ions. Examples include [[phosphoric acid]] H<sub>3</sub>PO<sub>4</sub>, and [[sulfuric acid]] H<sub>2</sub>SO<sub>4</sub>. In these compounds one or more hydroxide groups can [[dissociation (chemistry)|dissociate]] with the liberation of hydrogen cations as in a standard [[Brønsted–Lowry acid–base theory|Brønsted–Lowry]] acid. Many oxoacids of sulfur are known and all feature OH groups that can dissociate.<ref>Greenwood, p.&nbsp;705</ref>

[[Telluric acid]] is often written with the formula H<sub>2</sub>TeO<sub>4</sub>·2H<sub>2</sub>O but is better described structurally as Te(OH)<sub>6</sub>.<ref>Greenwood, p.&nbsp;781</ref>

Orthoperiodic acid<ref group=note>The name is '''not''' derived from "period", but from "iodine": periodic acid (compare [[iodic acid]], [[perchloric acid]]), and it is thus pronounced per-iodic {{IPAc-en|ˌ|p|ɜːr|aɪ|ˈ|ɒ|d|ᵻ|k}} {{respell|PUR|eye|OD|ik}}, and not as {{IPAc-en|ˌ|p|ɪər|ɪ|-}} {{respell|PEER|ee-}}.</ref> can lose all its protons, eventually forming the periodate ion [IO<sub>4</sub>]<sup>−</sup>. It can also be protonated in strongly acidic conditions to give the octahedral ion [I(OH)<sub>6</sub>]<sup>+</sup>, completing the [[isoelectronic]] series, [E(OH)<sub>6</sub>]<sup>''z''</sup>, E = Sn, Sb, Te, I; ''z'' = −2, −1, 0, +1. Other acids of iodine(VII) that contain hydroxide groups are known, in particular in salts such as the mesoperiodate ion that occurs in K<sub>4</sub>[I<sub>2</sub>O<sub>8</sub>(OH)<sub>2</sub>]·8H<sub>2</sub>O.<ref>Greenwood, pp.&nbsp;873–874</ref>

As is common outside of the alkali metals, hydroxides of the elements in lower oxidation states are complicated. For example, [[phosphorous acid]] H<sub>3</sub>PO<sub>3</sub> predominantly has the structure OP(H)(OH)<sub>2</sub>, in equilibrium with a small amount of P(OH)<sub>3</sub>.<ref>{{cite journal|title= Stabilization of tautomeric forms P(OH)<sub>3</sub> and HP(OH)<sub>2</sub> and their derivatives by coordination to palladium and nickel atoms in heterometallic clusters with the {{chem|Mo|3|MQ|4|4+}} core (M = Ni, Pd; Q = S, Se) |author=M. N. Sokolov |author2=E. V. Chubarova |author3=K. A. Kovalenko |author4=I. V. Mironov |author5=A. V. Virovets |author6=E. Peresypkina |author7=V. P. Fedin |doi= 10.1007/s11172-005-0296-1|year= 2005|journal= Russian Chemical Bulletin|volume= 54|pages= 615|issue= 3|s2cid=93718865 }}</ref><ref>Holleman, pp.&nbsp;711–718</ref>

The oxoacids of [[chlorine]], [[bromine]], and [[iodine]] have the formula O<sub>{{sfrac|''n''−1|2}}</sub>A(OH), where ''n'' is the [[oxidation number]]: +1, +3, +5, or +7, and A = Cl, Br, or I. The only oxoacid of [[fluorine]] is F(OH), [[hypofluorous acid]]. When these acids are neutralized the hydrogen atom is removed from the hydroxide group.<ref>Greenwood, p.&nbsp;853</ref>