Rubidium chromate

Structural formula
General
Surname	Rubidium chromate
Molecular formula	Rb 2 CrO 4
Brief description	yellow crystals
External identifiers / databases
EC number	236-601-1
ECHA InfoCard	100.033.260
PubChem	61605
Wikidata	Q2171580
properties
Molar mass	286.93 g · mol -1
Physical state	firmly
density	3.52 g cm −3
Melting point	994 ° C
solubility	good in water (620 g l −1 at 0 ° C, 736 g l −1 at 20 ° C)
safety instructions
H and P phrases	H: 272-317-350i-410
	P: 201-220-273-280-308 + 313-501
	As far as possible and customary, SI units are used. Unless otherwise noted, the data given apply to standard conditions .

Rubidium chromate is the rubidium salt of chromic acid .

Manufacturing

Rubidium chromate can be made from rubidium carbonate and rubidium dichromate .

{\ displaystyle \ mathrm {Rb_ {2} CO_ {3} + Rb_ {2} Cr_ {2} O_ {7} \ longrightarrow 2 \ Rb_ {2} CrO_ {4} + CO_ {2} \ uparrow}}

It is also possible to display it by reacting rubidium carbonate and chromium (VI) oxide

{\ displaystyle \ mathrm {Rb_ {2} CO_ {3} + CrO_ {3} \ longrightarrow Rb_ {2} CrO_ {4} + CO_ {2} \ uparrow}}

or rubidium dichromate with barium hydroxide .

{\ displaystyle \ mathrm {Rb_ {2} Cr_ {2} O_ {7} + Ba (OH) _ {2} \ longrightarrow BaCrO_ {4} + Rb_ {2} CrO_ {4} + H_ {2} O}}

properties

Rubidium chromate is a yellow solid with rhombic crystals that is easily soluble in water. The solubility increases with increasing temperature: 100 g of saturated solution contain 38.27 g at 0 ° C and 43.265 g of rubidium chromate at 25 ° C. It crystallizes in the orthorhombic crystal system with the space group Pnam (space group no. 62, position 6) and the lattice parameters a = 800.1 pm, b = 1072.2 pm and c = 607.4 pm, in the unit cell there are four formula units . The crystal structure is isotypic with that of potassium chromate and potassium sulfate . Template: room group / 62.6

Individual evidence

↑ ^a ^b ^c ^d ^e Jean D'Ans, Ellen Lax: Paperback for chemists and physicists. 3. Elements, inorganic compounds and materials, minerals, Volume 3. 4. Edition, Springer, 1997, ISBN 978-3-5406-0035-0 , p. 686 ( limited preview in the Google book search).
^ ^A ^b Dale L. Perry, Sidney L. Phillips: Handbook of inorganic compounds . CRC Press, 1995, ISBN 978-0-8493-8671-8 , pp. 333f. ( limited preview in Google Book search).
↑ ^a ^b Data sheet Rubidium chromate from Sigma-Aldrich , accessed on April 22, 2011 ( PDF ).
↑ 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 of compounds specified elsewhere in this Annex in the Classification and Labeling inventory of the European Chemicals Agency (ECHA), accessed on February 1, 2016. Manufacturers or distributors can expand the harmonized classification and labeling .
↑ ^a ^b ^c ^d Georg Brauer (Ed.) U. a .: Handbook of Preparative Inorganic Chemistry. 3rd, revised edition. Volume III, Ferdinand Enke, Stuttgart 1981, ISBN 3-432-87823-0 , p. 1525.

[Lax-1] Jean D'Ans, Ellen Lax: Paperback for chemists and physicists. 3. Elements, inorganic compounds and materials, minerals, Volume 3. 4. Edition, Springer, 1997, ISBN 978-3-5406-0035-0 , p. 686 ( limited preview in the Google book search).

[Perry-2] A ^b Dale L. Perry, Sidney L. Phillips: Handbook of inorganic compounds . CRC Press, 1995, ISBN 978-0-8493-8671-8 , pp. 333f. ( limited preview in Google Book search).

[Sigma-3] Data sheet Rubidium chromate from Sigma-Aldrich , accessed on April 22, 2011 ( PDF ).

[CLP_100.240.768-4] 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 of compounds specified elsewhere in this Annex in the Classification and Labeling inventory of the European Chemicals Agency (ECHA), accessed on February 1, 2016. Manufacturers or distributors can expand the harmonized classification and labeling .

[brauer-5] Georg Brauer (Ed.) U. a .: Handbook of Preparative Inorganic Chemistry. 3rd, revised edition. Volume III, Ferdinand Enke, Stuttgart 1981, ISBN 3-432-87823-0 , p. 1525.