Barium oxide 740875 221322260 2008-06-24T00:43:36Z Thijs!bot 1392310 robot Adding: [[ca:Òxid de bari]] {{Chembox new | Name = Barium oxide | OtherNames = Barium monoxide; barium protoxide; calcined baryta | Section1 = {{Chembox Identifiers | CASNo = 1304-28-5 }} | Section2 = {{Chembox Properties | Formula = BaO | MolarMass = 153.3 g/mol | Appearance = white solid | Density = 5.7 g/cm³, solid | Solubility = 3.8 g/100 ml (20 °C) | MeltingPt = 1923 °C | BoilingPt = ~2000 °C }} | Section3 = {{Chembox Structure | Coordination = [[octahedron|Octahedral]] | CrystalStruct = [[cubic]] }} | Section7 = {{Chembox Hazards | EUClass = Harmful ('''Xn''') | RPhrases = {{R20/22}} | SPhrases = {{S2}}, {{S28}} | FlashPt = non-flammable }} | Section8 = {{Chembox Related | OtherAnions = [[Barium hydroxide]]<br />[[Barium peroxide]] | OtherCations = [[Calcium oxide]]<br />[[Strontium oxide]] }} }} '''Barium oxide''', BaO, is a white [[hygroscopic]] [[chemical compound|compound]] formed by the burning of [[barium]] in [[oxygen]], although it is often formed through the decomposition of other [[barium compounds|barium salts]].<ref> {{cite web | title = Compounds of barium: barium (II) oxide | work = Web Elements | publisher = The University of Sheffield | date = 2007-01-26 | url = http://www.webelements.com/webelements/compounds/text/Ba/Ba1O1-1304285.html | accessdate = 2007-02-22 }}</ref> : 2Ba + O<sub>2</sub> → 2BaO : BaCO<sub>3</sub> → BaO + CO<sub>2</sub> It transforms into [[barium hydroxide]] on contact with water. : BaO + H<sub>2</sub>O → Ba(OH)<sub>2</sub> ==Uses== Barium oxide is used as a coating for [[hot cathode]]s, and in [[cathode ray tube]]s. It is used in the production of certain kinds of glass such as optical [[crown glass (optics)|crown glass]]. It replaced [[lead oxide]]. Lead oxide was used to raise the [[refractive index]], but it also raised the dispersive power. Barium oxide only raises the refractive index.<ref> {{cite web | title = Barium Oxide (chemical compound) | work = Encyclopædia Britanica | publisher = Encyclopædia Britanica | date = 2007 | url = http://www.britannica.com/eb/topic-53368/barium-oxide | accessdate = 2007-02-19 }}</ref> Barium oxide also has use as an [[Ethoxylation|ethoxylation catalyst]] in the reaction of [[ethylene oxide]] and [[alcohol]]s, which takes place between 150 and 200°C.<ref>{{Citation | last = Nield | first = Gerald | last2 = Washecheck | first2 = Paul | last3 = Yang | first3 = Kang | title = United States Patent 4210764 | date = 05-04 | year = 1979 | url = http://www.freepatentsonline.com/4210764.html | access-date = 2007-02-20 }}</ref> ==Safety issues== Barium oxide is an [[irritant]]. If it contacts the skin or the eyes or is inhaled it causes pain and redness. However, it is more dangerous when ingested. It can cause [[nausea|nausea]] and [[diarrhea|diarrhea]], [[paralysis|muscle paralysis]], cardiac arrhythmia, and can cause death. If ingested, medical attention should be sought immediately. Barium oxide also is dangerous to the environment. It is harmful especially to [[Marine biology|aquatic organisms]]<ref> {{cite web | title = Barium Oxide (ICSC) | publisher = IPCS | date = October 1999 | url = http://www.inchem.org/documents/icsc/icsc/eics0778.htm | accessdate = 2007-02-19 }}</ref> ==References== <references/> ==External links== *[http://www.ilo.org/public/english/protection/safework/cis/products/icsc/dtasht/_icsc07/icsc0778.htm International Chemical Safety Card 0778] [[Category:Barium compounds]] [[Category:Oxides]] [[ar:أكسيد باريوم]] [[ca:Òxid de bari]] [[da:Bariumoxid]] [[de:Bariumoxid]] [[lv:Bārija oksīds]] [[ja:酸化バリウム]] [[pl:Tlenek baru]] [[pt:Óxido de bário]] [[vi:Ôxít bari]] [[zh:氧化钡]]