Editing Halogen (section)

===== Reactions with water =====
Fluorine reacts vigorously with water to produce [[oxygen]] (O<sub>2</sub>) and [[hydrogen fluoride]] (HF):<ref>{{cite web| url = http://www.chemguide.co.uk/inorganic/group7/halogensasoas.html | title = The Oxidising Ability of the Group 7 Elements | publisher =  Chemguide.co.uk|access-date = 2011-12-29}}</ref>

: {{math|2 F<sub>2</sub>(g) + 2 H<sub>2</sub>O(l) → O<sub>2</sub>(g) + 4 HF(aq)}}

Chlorine has maximum solubility of ca. 7.1 g Cl<sub>2</sub> per kg of water at ambient temperature (21&nbsp;°C).<ref>{{cite web | url =http://www.resistoflex.com/chlorine_graphs.htm#9 | title =Solubility of chlorine in water | publisher =Resistoflex.com | access-date =2011-12-29 | archive-date =2012-04-23 | archive-url =https://web.archive.org/web/20120423014139/http://www.resistoflex.com/chlorine_graphs.htm#9 | url-status =dead }}</ref>  Dissolved chlorine reacts to form [[hydrochloric acid]] (HCl) and [[hypochlorous acid]], a solution that can be used as a [[disinfectant]] or [[bleach]]:

: {{math|Cl<sub>2</sub>(g) + H<sub>2</sub>O(l) → HCl(aq) + HClO(aq)}}

Bromine has a solubility of 3.41 g per 100 g of water,<ref>{{cite web|url=http://www.bromaid.org/hand_chap1.htm |title=Properties of bromine |publisher=bromaid.org |url-status=dead |archive-url=https://web.archive.org/web/20071208113138/http://www.bromaid.org/hand_chap1.htm |archive-date=December 8, 2007 }}</ref> but it slowly reacts to form [[hydrogen bromide]] (HBr) and [[hypobromous acid]] (HBrO):

: {{math|Br<sub>2</sub>(g) + H<sub>2</sub>O(l) → HBr(aq) + HBrO(aq)}}

Iodine, however, is minimally soluble in water (0.03 g/100 g water at 20&nbsp;°C) and does not react with it.<ref>{{cite web| url =http://hazard.com/msds/mf/baker/baker/files/i2680.htm | title = Iodine MSDS  |publisher=Hazard.com |date =1998-04-21 |access-date =2011-12-29}}</ref>  However, iodine will form an aqueous solution in the presence of iodide ion, such as by addition of [[potassium iodide]] (KI), because the [[triiodide]] ion is formed.