Tellurium trioxide

Tellurium trioxide
Other names

tellurium(VI) oxide
Identifiers
CAS number 13451-18-8
PubChem 83481
ChemSpider 75319 Y
Jmol-3D images Image 1
Properties
Molecular formula TeO3
Molar mass 175.6 g/mol
Appearance yellow-orange crystals (α-TeO3)
Density 5.07 g/cm³, solid
Melting point

430°C
Hazards
EU classification not listed
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Except where noted otherwise, data are given for materials in their standard state (at 25 °C, 100 kPa)
Infobox references

Tellurium trioxide (TeO3) is an inorganic chemical compound of tellurium and oxygen. In this compound, tellurium is in the +6 oxidation state.

Polymorphs

There are two forms, yellow-red α-TeO3 and grey, rhombohedral, β-TeO3 which is less reactive.[1]
α-TeO3 has a structure similar to FeF3 with octahedral TeO6 units that share all vertices.[2]

Preparation

α-TeO3 can be prepared by heating orthotelluric acid, Te(OH)6 at over 300°C .[1] 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.[2] With alkalis it forms tellurates.[2]
α-TeO3 when heated loses oxygen to form firstly Te2O5 and then TeO2.[1]

References

  1. ^ a b c Inorganic Chemistry,Egon Wiberg, Arnold Frederick Holleman Elsevier 2001 ISBN 0-12-352651-5
  2. ^ a b c Greenwood, Norman N.; Earnshaw, Alan (1997). Chemistry of the Elements (2nd ed.). Oxford: Butterworth-Heinemann. ISBN 0080379419.