Tellurium trioxide

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OtherNames = tellurium(VI) oxide
Section1 = Chembox Identifiers
CASNo = 13451-18-8
Section2 = Chembox Properties
Formula = TeO₃
MolarMass = 175.6 g/mol
Appearance = yellow-orange crystals (α-TeO₃)
Density = 5.07 g/cm³, solid
MeltingPt = 430°C
BoilingPt =
Section3 = Chembox Structure
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Section7 = Chembox Hazards
EUClass = not listed

Tellurium trioxide (TeO₃) is an inorganic chemical compound of tellurium and oxygen. Tellurium is in the +6 oxidation state. There are two forms, yellow-red α-TeO₃ and grey, rhombohedral, β-TeO₃ which is less reactive."Inorganic Chemistry",Egon Wiberg, Arnold Frederick Holleman Elsevier 2001 ISBN 0123526515]
α-TeO₃ has a structure similar to FeF₃ with octahedral TeO₆ units that share all vertices.Greenwood&Earnshaw]
α-TeO3 can be prepared by heating orthotelluric acid, Te(OH)₆ at over 300°C ."Inorganic Chemistry",Egon Wiberg, Arnold Frederick Holleman Elsevier 2001 ISBN 0123526515] The β-TeO₃ form can be prepared by heating α-TeO₃ in a sealed tube with O₂ and H₂SO₄.
α-TeO₃ is unreactive to water but is a powerful oxidising agent when heated. With alkalis it forms tellurates.
α-TeO₃ when heated loses oxygen to form firstly Te₂O₅ and then TeO₂."Inorganic Chemistry",Egon Wiberg, Arnold Frederick Holleman Elsevier 2001 ISBN 0123526515]

References