Disodium hydrogen arsenate

Structural formula
General
Surname	Disodium hydrogen arsenate
other names	Disodium arsenate
Molecular formula	Na 2 HAsO 4
Brief description	white solid
External identifiers / databases
ECHA InfoCard	100.029.002
PubChem	24500
Wikidata	Q2557463
properties
Molar mass	185.91 g mol −1
Physical state	firmly
density	1.87 g cm −3 (heptahydrate); 1.74 g cm −3 (dodecahydrate);
solubility	soluble in water and glycerol
safety instructions
H and P phrases	H: 301-331-350-410
	P: 201-261-301 + 310-273-311-501
MAK	Switzerland: 0.01 mg m −3 (based on arsenic, measured as inhalable dust )
	As far as possible and customary, SI units are used. Unless otherwise noted, the data given apply to standard conditions .

Disodium hydrogen arsenate is an inorganic chemical compound of sodium from the group of arsenates .

Extraction and presentation

Disodium hydrogen arsenate can be obtained by heating sodium dihydrogen arsenate above 50 ° C. This passes via the stages of disodium hydrogen arsenate NaH ₂ AsO ₄ → Na ₂ HAsO ₄ → Na ₂ H ₂ As ₂ O ₇ → Na ₃ H ₂ As ₃ O ₁₀ finally above 230 ° C into polymeric sodium metaarsenate NaAsO ₃ . The dehydration products react with water vapor, whereby the same steps can be detected as in the case of dehydration.

properties

Disodium hydrogen arsenate is a white solid. It decomposes when heated above 90 ° C. The heptahydrate and dodecahydrate have a monoclinic crystal structure .

use

Disodium hydrogen arsenate heptahydrate can be used as a reference for the quantification of arsenic compounds in rice- and seafood-based samples using ion chromatography - ICP-MS . Sodium hydrogen arsenate heptahydrate is used as a source of soluble arsenic and in dyeing and printing with turkey red oil. It is also used as a veterinary medicine for parasites, skin diseases, blood diseases, rheumatism and asthma.

Individual evidence

↑ ^a ^b ^c ^d ^e ^f Entry on disodium hydrogen arsenate in the GESTIS substance database of the IFA , accessed on October 16, 2016(JavaScript required) .
^ ^A ^b American Chemical Society, American Chemical Society. Committee on Analytical Reagents: Reagent Chemicals Specifications and Procedures: American Chemical Society Specifications, Official from January 1, 2006 . American Chemical Society, 2006, ISBN 978-0-8412-3945-6 , pp. 582 ( limited preview in Google Book search).
^ ^A ^b R. Blachnik: Pocket book for chemists and physicists Volume 3: Elements, inorganic compounds and materials, minerals . Springer-Verlag, 2013, ISBN 978-3-642-58842-6 , pp. 600 ( limited preview in Google Book Search).
↑ ^a ^b Data sheet Sodium hydrogen arsenate heptahydrate, ACS, 98.0-102.0% from AlfaAesar, accessed on October 16, 2016 ( PDF )(JavaScript required) .
↑ Not explicitly listed in Regulation (EC) No. 1272/2008 (CLP) , but with the specified labeling it falls under the group entry arsenic compounds, with the exception of those named in this appendix in the Classification and Labeling Inventory of the European Chemicals Agency (ECHA) on February 6, 2019. Manufacturers or distributors can expand the harmonized classification and labeling .
↑ Swiss Accident Insurance Fund (Suva): Limit values - current MAK and BAT values (search for arsenic and inorganic arsenic compounds ), accessed on March 4, 2020.
↑ Harry J. Emeleus, JS Anderson: Results and Problems of Modern Inorganic Chemistry . Springer-Verlag, 2013, ISBN 978-3-642-86628-9 , pp. 531 ( limited preview in Google Book search).
↑ Georg Brauer (Ed.), With the collaboration of Marianne Baudler a . a .: Handbook of Preparative Inorganic Chemistry. 3rd, revised edition. Volume I, Ferdinand Enke, Stuttgart 1975, ISBN 3-432-02328-6 , p. 581.
↑ Data sheet Sodium arsenate dibasic heptahydrate, ≥98.0% from Sigma-Aldrich , accessed on October 16, 2016 ( PDF ).

[GESTIS-1] ↑ ^a ^b ^c ^d ^e ^f Entry on disodium hydrogen arsenate in the GESTIS substance database of the IFA , accessed on October 16, 2016(JavaScript required) .

[American_Chemical_Society,_American_Chemical_Society._Committee_on_Analytical_Reagents-2] A ^b American Chemical Society, American Chemical Society. Committee on Analytical Reagents: Reagent Chemicals Specifications and Procedures: American Chemical Society Specifications, Official from January 1, 2006 . American Chemical Society, 2006, ISBN 978-0-8412-3945-6 , pp. 582 ( limited preview in Google Book search).

[R._Blachnik-3] A ^b R. Blachnik: Pocket book for chemists and physicists Volume 3: Elements, inorganic compounds and materials, minerals . Springer-Verlag, 2013, ISBN 978-3-642-58842-6 , pp. 600 ( limited preview in Google Book Search).

[Alfa-4] Data sheet Sodium hydrogen arsenate heptahydrate, ACS, 98.0-102.0% from AlfaAesar, accessed on October 16, 2016 ( PDF )(JavaScript required) .

[CLP_100.240.769-5] Not explicitly listed in Regulation (EC) No. 1272/2008 (CLP) , but with the specified labeling it falls under the group entry arsenic compounds, with the exception of those named in this appendix in the Classification and Labeling Inventory of the European Chemicals Agency (ECHA) on February 6, 2019. Manufacturers or distributors can expand the harmonized classification and labeling .

[6] Swiss Accident Insurance Fund (Suva): Limit values - current MAK and BAT values (search for arsenic and inorganic arsenic compounds ), accessed on March 4, 2020.

[Harry_J._Emeleus,_J.S._Anderson-7] Harry J. Emeleus, JS Anderson: Results and Problems of Modern Inorganic Chemistry . Springer-Verlag, 2013, ISBN 978-3-642-86628-9 , pp. 531 ( limited preview in Google Book search).

[brauer-8] Georg Brauer (Ed.), With the collaboration of Marianne Baudler a . a .: Handbook of Preparative Inorganic Chemistry. 3rd, revised edition. Volume I, Ferdinand Enke, Stuttgart 1975, ISBN 3-432-02328-6 , p. 581.

[Sigma-9] Data sheet Sodium arsenate dibasic heptahydrate, ≥98.0% from Sigma-Aldrich , accessed on October 16, 2016 ( PDF ).