Tellurite

This article is about the ion. For the mineral, see Tellurite (mineral).

Tellurite

Names
Systematic IUPAC name Tellurite (substitutive) Trioxidotellurate(2−) (additive)
Identifiers
CAS Number	15852-22-9
3D model (JSmol)	Interactive image
ChEBI	CHEBI:30477
ChemSpider	102958 Y
Gmelin Reference	100741
PubChem CID	115037
CompTox Dashboard (EPA)	DTXSID10894775
InChI InChI=1S/H2O3Te/c1-4(2)3/h(H2,1,2,3)/p-2 Y Key: SITVSCPRJNYAGV-UHFFFAOYSA-L Y
SMILES [O-][Te+]([O-])[O-]
Properties
Chemical formula	O3Te2−
Molar mass	175.6 g mol−1
Conjugate acid	Tellurous acid
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). Infobox references

The tellurite ion is TeO²⁻
₃. A tellurite (compound), for example sodium tellurite, is a compound that contains this ion. They are typically colorless or white salts, which in some ways are comparable to sulfite. A mineral with the formula TeO₂ is called tellurite.

Structure and reactions

Crystal structure of sodium tellurite, highlighting the pyramidal structure of the anion.

Tellurite dianion is pyramidal, like selenite and sulfite. The anion has C_3v symmetry.

Tellurites can be reduced to elemental tellurium by electrolysis or a strong reducing agent. When fused with nitrate salts, tellurite salts oxidize to tellurates (TeO²⁻
₄).

Upon acidification of aqueous solutions of tellurite salts, solid hydrated tellurium dioxide (TeO₂) precipitates. This reaction allows the separation of tellurium from selenium since selenous acid remains soluble at low pH. The intermediate in the protonation occurs at oxygen to give [TeO₂(OH)]⁻.

Uses

Potassium tellurite (K₂TeO₃) is used together with agar as part of a selective medium for growth of some bacteria (Clauberg medium). Corynebacteria and some other species reduce TeO²⁻
₃ to elemental Te, which stains the bacteria black.

See also

• List of tellurites

Further reading

• M. R. Masson, H. D. Lutz and B. Engelen (eds.) "Sulfites, Selenites and Tellurites", Pergamon Press, Oxford, 1986.