Antimony trioxide 2067882 197515860 2008-03-11T17:44:03Z SmackBot 433328 Date the maintenance tags or general fixes {{Chembox new | Name = Antimony trioxide | ImageFile = Antimony trioxide.jpg <!-- | ImageSize = 200px --> | ImageName = Antimony trioxide | OtherNames = Antimony(III) oxide<br />Antimony [[sesquioxide]]<br />Antimonous oxide | Section1 = {{Chembox Identifiers | CASNo = 1309-64-4 }} | Section2 = {{Chembox Properties | Formula = Sb<sub>2</sub>O<sub>3</sub> | MolarMass = 291.52 g/mol | Appearance = white solid | Density = 5.2 g/cm³, α-form | Solubility = 1.4 mg/100 mL (30 °C) | MeltingPt = 656 °C | BoilingPt = 1425 °C | pKa = }} | Section3 = {{Chembox Structure | Coordination = pyramidal | CrystalStruct = [[Cubic crystal system|cubic]] (α)<570 °C<br />[[orthorhombic]] (β) >570 °C | Dipole = zero }} | Section7 = {{Chembox Hazards | ExternalMSDS = | EUClass = Harmful ('''Xn''')<br />Carc. Cat. 3 | NFPA-R = 4 | RPhrases = {{R40}} | SPhrases = {{S2}}, {{S22}}, {{S36/37}} }} | Section8 = {{Chembox Related | OtherAnions = [[Antimony trisulfide]] | OtherCations = [[Arsenic trioxide]]<br />[[Bismuth trioxide]] | OtherCpds = [[Diantimony tetraoxide]]<br />[[Antimony pentoxide]] }} }} '''Antimony trioxide''' is the [[chemical compound]] with the [[Chemical formula|formula]] Sb<sub>2</sub>O<sub>3</sub>. It is the most important commercial compound of [[antimony]]. ==Preparation== As the primary oxide of antimony, Sb<sub>2</sub>O<sub>3</sub> is prepared by burning elemental antimony in air: :4Sb + 3O<sub>2</sub> &rarr; 2Sb<sub>2</sub>O<sub>3</sub> Alternatively, [[antimonide]] minerals can be roasted to give the same products. ==Structure== The structure of Sb<sub>2</sub>O<sub>3</sub> depends on the temperature of the sample. Only at very high temperatures does the molecule Sb<sub>2</sub>O<sub>3</sub> exist.{{vague|date=March 2008}} At moderate temperatures, the gas consists of Sb<sub>4</sub>O<sub>6</sub>. These molecules are bicyclic cages, similar to the related oxide of phosphorus, [[phosphorus trioxide]]. The cage structure is retained in a solid that crystallizes in a cubic habit. The Sb-O distance is 1.977 Å and the O-Sb-O angle of 95.6°.<ref> C. Svensson “Refinement of the crystal structure of cubic antimony trioxide, Sb<sub>2</sub>O<sub>3</sub>” Acta Crystographica, 1975, volume B31, pp. 2016-2018. doi:10.1107/S0567740875006759.</ref> This materials exists in nature as the [[mineral]] senarmontite. Below 606 °C, the more stable form of is [[orthorhombic]], consisting of pairs -Sb-O-Sb-O- chains that are linked by oxide bridges between the Sb centers. This form exists in nature as the mineral [[valentinite]].<ref>Wells, A.F. (1984) Structural Inorganic Chemistry, Oxford: Clarendon Press. ISBN 0-19-855370-6.</ref> Antimony trioxide is an [[amphoteric oxide]], dissolving in alkaline solution to give [[antimonite]]s and in acid solution to given a range of polyantimonous acids. It can be readily oxidized to antimony pentoxide or other antimony(V) compounds, but is also easily reduced to antimony, sometimes with production of [[stibine]]. ==Uses== The annual consumption of antimony trioxide in the [[United States]] is approximately 10,000 [[tonne]]s. *[[Flame retardant]] for textiles, polymers, and coatings *Opacifying agent for [[glass]]es, [[ceramic]]s and [[Vitreous enamel|enamel]]s *[[Pigment]] '''antimony white''' ==Toxicology== Antimony trioxide is only weakly absorbed by the digestive system, and the main route of exposure is by inhalation of the dust. The elimination of antimony from the body is slow, leading to a risk of chronic toxicity in the form of [[pneumoconiosis]] with repeated inhalation exposures. Acute poisoning is very rare, and the signs are fairly non-characteristic ([[vomiting]], abdominal pain, irritation of the [[mucous membrane]]s, [[diarrhea]], cardiac irregularities). These symptoms are more often associated with ingestion of other more water soluble compounds. Chronic poisoning by antimony trioxide is also rare. The main signs are irritation of the respiratory tract and of the skin and a characteristic [[pneumoconiosis]], which is visible on chest X-rays. Antimony trioxide is known to pass into [[breast milk]] and to transverse the [[placenta]] only in very small amounts. One study of exposed female workers suggested a higher incidence than usual of [[menstrual]] problems and of late-term [[miscarriage]]s; also their children may have developed slower than usual during the first twelve months of life, although this study is inconclusive. A more recent developmental study in rodents did not confirm an effect on mammalian development. ==References== <references/> ==Further reading== * Institut national de recherche et de sécurité (INRS), ''Fiche toxicologique nº 198&nbsp;: Trioxyde de diantimoine'', 1992. * Inhalation Developmental Toxicity Studies In Rats With Antimony Trioxide (Sb2O3). Newton PE; Schroeder RE; Zwick L; Serex T; Toxicologist 2004 Mar;78(1-S):38 * The Oxide Handbook, G.V. Samsonov, 1981, 2nd ed. IFI/Plenum, ISBN 0-306-65177-7 ==External links== * [http://www.ilo.org/public/english/protection/safework/cis/products/icsc/dtasht/_icsc00/icsc0012.htm International Chemical Safety Card 0012] * [http://ecb.jrc.it/ European Chemicals Bureau] * [http://www.antimonynet.com/ AntimonyNet(news,price,ore,analysis,etc)] [[Category:Antimony compounds]] [[Category:Oxides]] [[Category:Inorganic pigments]] [[ar:أكسيد أنتيموان ثلاثي]] [[cs:Oxid antimonitý]] [[de:Antimon(III)-oxid]] [[es:Trióxido de antimonio]] [[ja:三酸化アンチモン]] [[pl:Tlenek antymonu(III)]] [[sk:Oxid antimonitý]] [[zh:三氧化二锑]]