Cesium dichromate

Structural formula
General
Surname	Cesium dichromate
Molecular formula	Cr 2 Cs 2 O 7
Brief description	orange-red solid
External identifiers / databases
EC number	236-879-4
ECHA InfoCard	100.033.512
Wikidata	Q15276735
properties
Molar mass	481.80 g mol −1
Physical state	firmly
solubility	poorly soluble in cold water
safety instructions
H and P phrases	H: 350-272-410-317
	P: 221-210-302 + 352-321-405-501
	As far as possible and customary, SI units are used. Unless otherwise noted, the data given apply to standard conditions .

Cesium dichromate is a chemical compound from the group of chromates .

Extraction and presentation

Cesium dichromate can be obtained by reacting ammonium dichromate with cesium chloride .

{\ displaystyle {\ ce {(NH4) 2Cr2O7 + 2CsCl -> Cs2Cr2O7 + 2NH4Cl}}}

properties

Cesium dichromate is an orange-red hygroscopic solid that is sparingly soluble in cold and easily soluble in hot water. It has a monoclinic crystal structure with the space group A 2 / a (space group no. 15, position 4) . Template: room group / 15.4

If cesium dichromate is heated with zirconium , it reacts to form elemental cesium, chromium (III) oxide and zirconium (IV) oxide .

{\ displaystyle {\ ce {Cs2Cr2O7 + 2Zr -> 2Cs + 2ZrO2 + Cr2O3}}}

use

A mixture of cesium dichromate and zirconium can be used to make elemental cesium and in vacuum tubes . When the mixture is heated, cesium in vapor form is also produced there, which reacts with residual traces of water or oxygen and thus ensures a better vacuum .

Individual evidence

↑ ^a ^b ^c ^d Georg Brauer: Handbook of preparative inorganic chemistry . 3., reworked. Edition. tape III . Enke, Stuttgart 1981, ISBN 3-432-87823-0 , pp. 1526 .
↑ ^a ^b ^c data sheet Cesium dichromate, 99.8% (metals basis) from AlfaAesar, accessed on June 30, 2013 ( PDF )(JavaScript required) .
↑ Not explicitly listed in Regulation (EC) No. 1272/2008 (CLP) , but with the specified labeling it falls under the group entry Chromium (VI) compounds, with the exception of barium chromate and compounds that are listed separately in this appendix in Classification and Labeling Inventory of the European Chemicals Agency (ECHA), accessed on June 11, 2019. Manufacturers or distributors can expand the harmonized classification and labeling .
↑ Roger Blachnik (Ed.): Paperback for chemists and physicists . Volume III: Elements, Inorganic Compounds and Materials, Minerals . founded by Jean d'Ans, Ellen Lax. 4th, revised and revised edition. Springer, Berlin 1998, ISBN 3-540-60035-3 , pp. 396 f . ( limited preview in Google Book search).
↑ ^a ^b Entry on cesium compounds. In: Römpp Online . Georg Thieme Verlag, accessed on June 27, 2014.
^ AF Holleman , E. Wiberg , N. Wiberg : Textbook of Inorganic Chemistry . 101st edition. Walter de Gruyter, Berlin 1995, ISBN 3-11-012641-9 , p. 1162.

[brauer-1] Georg Brauer: Handbook of preparative inorganic chemistry . 3., reworked. Edition. tape III . Enke, Stuttgart 1981, ISBN 3-432-87823-0 , pp. 1526 .

[Alfa-2] ta sheet Cesium dichromate, 99.8% (metals basis) from AlfaAesar, accessed on June 30, 2013 ( PDF )(JavaScript required) .

[CLP_100.240.768-3] Not explicitly listed in Regulation (EC) No. 1272/2008 (CLP) , but with the specified labeling it falls under the group entry Chromium (VI) compounds, with the exception of barium chromate and compounds that are listed separately in this appendix in Classification and Labeling Inventory of the European Chemicals Agency (ECHA), accessed on June 11, 2019. Manufacturers or distributors can expand the harmonized classification and labeling .

[Jean_d’Ans,_Ellen_Lax,_Roger_Blachnik-4] Roger Blachnik (Ed.): Paperback for chemists and physicists . Volume III: Elements, Inorganic Compounds and Materials, Minerals . founded by Jean d'Ans, Ellen Lax. 4th, revised and revised edition. Springer, Berlin 1998, ISBN 3-540-60035-3 , pp. 396 f . ( limited preview in Google Book search).

[roempp-5] Entry on cesium compounds. In: Römpp Online . Georg Thieme Verlag, accessed on June 27, 2014.

[Arnold_F._Holleman,_Egon_Wiberg,_Nils_Wiberg-6] AF Holleman , E. Wiberg , N. Wiberg : Textbook of Inorganic Chemistry . 101st edition. Walter de Gruyter, Berlin 1995, ISBN 3-11-012641-9 , p. 1162.