Calcium tellurite

Crystal structure
	__ Ca 2+ __ Te 4+ __ O 2−
General
Surname	Calcium tellurite
Ratio formula	CaTeO 3
External identifiers / databases
EC number	237-459-3
ECHA InfoCard	100.034.040
PubChem	21124564
Wikidata	Q15993180
properties
Molar mass	215.68 g mol −1
Physical state	firmly
Melting point	1072 ° C
safety instructions
GHS hazard labeling ; no classification available
GHS hazard labeling ; no classification available
	As far as possible and customary, SI units are used. Unless otherwise noted, the data given apply to standard conditions .

Calcium tellurite is an inorganic chemical compound of calcium from the group of tellurites with the empirical formula CaTeO ₃ . With CaTe ₃ O ₈ ( Carlfriesite ), CaTe ₂ O ₅ and Ca ₄ Te ₅ O ₁₄ , three other calcium tellurites are known.

Extraction and presentation

Calcium tellurite can be obtained by reacting calcium oxide with tellurium dioxide under an inert gas.

{\ displaystyle {\ ce {CaO + TeO2 -> CaTeO3}}}

It can also be obtained by reacting a solution of calcium chloride or calcium nitrate with sodium tellurite to form the monohydrate.

{\ displaystyle {\ ce {CaCl2 + Na2TeO3 -> CaTeO3 * H2O + 2NaCl}}}

Synthesis by reaction of calcium chloride with tellurium dichloride in water is also possible.

{\ displaystyle {\ ce {CaCl2 + 2 TeCl2 + 3H2O -> Te + CaTeO3 * H2O + 6 HCl}}}

properties

Calcium tellurite occurs in several crystal structures, the low temperature form being stable up to 882 ° C. It has an orthorhombic crystal structure with the space group P 2 ₁ca (space group no. 29, position 4) and the monohydrate has a crystal structure with the space group P 2 ₁cn (no. 33, position 4) . Template: room group / 29.4Template: room group / 33.4

use

Calcium tellurite can be used to make telluric acid .

Individual evidence

↑ ^a ^b ^c ^d ^e ^f Richard C. Ropp: Encyclopedia of the Alkaline Earth Compounds . Newnes, 2012, ISBN 0-444-59553-8 , pp. 106 ( limited preview in Google Book search).
↑ This substance has either not yet been classified with regard to its hazardousness or a reliable and citable source has not yet been found.
↑ E. Schweizerbart: Advances in Mineralogy, Volumes 46-47 . 1969, p. 55 ( limited preview in Google Book search).
↑ SN Tripathi, R. Mishra et al. a .: X-ray powder diffraction investigation of new high temperature polymorphs of CaTeO3 and CaTe2O5. In: Powder Diffraction. 16, 2001, p. 205, doi : 10.1154 / 1.1377012 .
↑ Berthold Stöger, Matthias Weil u. a .: Polymorphism of CaTeO3 and solid solutions Ca (x) Sr (1-x) TeO3. In: Acta Crystallographica Section B Structural Science. 65, 2009, p. 167, doi : 10.1107 / S0108768109002997 .
↑ Morgane Poupon, Nicolas Barrier et al. a .: Hydrothermal Synthesis and Dehydration of CaTeO3 (H2O): An Original Route to Generate New CaTeO3 Polymorphs In: Inorganic Chemistry. 54, 2015, p. 5660, doi : 10.1021 / acs.inorgchem.5b00037 .
↑ Erich Pietsch: Tellurium . Springer-Verlag, 2013, ISBN 978-3-662-13092-6 , pp. 288 ( limited preview in Google Book search).

[Richard_C._Ropp-1] ↑ ^a ^b ^c ^d ^e ^f Richard C. Ropp: Encyclopedia of the Alkaline Earth Compounds . Newnes, 2012, ISBN 0-444-59553-8 , pp. 106 ( limited preview in Google Book search).

[NV-2] This substance has either not yet been classified with regard to its hazardousness or a reliable and citable source has not yet been found.

[3] E. Schweizerbart: Advances in Mineralogy, Volumes 46-47 . 1969, p. 55 ( limited preview in Google Book search).

[DOI10.1154/1.1377012-4] SN Tripathi, R. Mishra et al. a .: X-ray powder diffraction investigation of new high temperature polymorphs of CaTeO3 and CaTe2O5. In: Powder Diffraction. 16, 2001, p. 205, doi : 10.1154 / 1.1377012 .

[DOI10.1107/S0108768109002997-5] Berthold Stöger, Matthias Weil u. a .: Polymorphism of CaTeO3 and solid solutions Ca (x) Sr (1-x) TeO3. In: Acta Crystallographica Section B Structural Science. 65, 2009, p. 167, doi : 10.1107 / S0108768109002997 .

[DOI10.1021/acs.inorgchem.5b00037-6] Morgane Poupon, Nicolas Barrier et al. a .: Hydrothermal Synthesis and Dehydration of CaTeO3 (H2O): An Original Route to Generate New CaTeO3 Polymorphs In: Inorganic Chemistry. 54, 2015, p. 5660, doi : 10.1021 / acs.inorgchem.5b00037 .

[Erich_Pietsch-7] Erich Pietsch: Tellurium . Springer-Verlag, 2013, ISBN 978-3-662-13092-6 , pp. 288 ( limited preview in Google Book search).