Editing Barium hydroxide (section)

==Reactions==
Barium hydroxide decomposes to [[barium oxide]] when heated to 800&nbsp;°C.  Reaction with [[carbon dioxide]] gives [[barium carbonate]]. Its aqueous solution, being highly alkaline, undergoes neutralization reactions with acids. It is especially useful on reactions that require the titrations of weak organic acids. Thus, it forms [[barium sulfate]] and [[barium phosphate]] with sulfuric  and phosphoric acids, respectively.  Reaction with [[hydrogen sulfide]] produces [[barium sulfide]].  Precipitation of many insoluble, or less soluble barium salts, may result from double replacement reaction when a barium hydroxide aqueous solution is mixed with many solutions of other metal salts.<ref>Pradyot Patnaik. ''Handbook of Inorganic Chemicals''. McGraw-Hill, 2002, {{ISBN|0-07-049439-8}}</ref>

Reactions of barium hydroxide with [[ammonium]] salts are strongly [[endothermic]]. The reaction of barium hydroxide octahydrate with [[ammonium chloride]]<ref name=UCSD>{{cite web|title=Endothermic Reactions of Hydrated Barium Hydroxide and Ammonium Chloride|url=http://www-chem.ucsd.edu/undergraduate/teaching-labs/demos/demo45.html|publisher=UC San Diego|access-date=2 April 2014}}</ref><ref>[http://www.nuffieldfoundation.org/practical-chemistry/endothermic-solid-solid-reactions Endothermic Solid-Solid Reactions]</ref> or<ref name=UW /> [[ammonium thiocyanate]]<ref name=UW>{{cite web|last=Camp|first=Eric|title=Endothermic Reaction|url=http://depts.washington.edu/chem/facilserv/lecturedemo/EndothermicReaction-UWDept.ofChemistry.html|publisher=Univertist of Washington|access-date=2 April 2014}}</ref><ref name=RSC>{{cite web|title=Endothermic solid-solid reactions |url=http://media.rsc.org/Classic%20Chem%20Demos/CCD-44.pdf |work=Classic Chemistry Demonstrations |publisher=The Royal Society of Chemistry |access-date=2 April 2014 |url-status=dead |archive-url=https://web.archive.org/web/20140407092124/http://media.rsc.org/Classic%20Chem%20Demos/CCD-44.pdf |archive-date=7 April 2014 }}</ref> is often used as a classroom chemistry demonstration, producing temperatures cold enough to freeze water and enough water to dissolve the resulting mixture.