Copper (II) arsenate

Structural formula
General
Surname	Copper (II) arsenate
other names	Copper (II) arsenate (V); Copper (II) orthoarsenate;
Molecular formula	Cu 3 (AsO 4 ) 2
Brief description	blue-green solid
External identifiers / databases
PubChem	26065
Wikidata	Q976206
properties
Molar mass	468.46 g mol −1
Physical state	firmly
density	5.18 g cm −3 ; 3.86 g cm −3 (tetrahydrate);
solubility	Easily soluble in hydrochloric acid; insoluble in water; soluble in dilute acids and ammonia water;
safety instructions
H and P phrases	H: 301-331-410
	P: ?
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 .

Copper (II) arsenate is a chemical compound of copper from the group of arsenates . It is the copper (II) salt of arsenic acid .

Occurrence

Copper (II) arsenate occurs naturally in the form of the mineral lammerite and as a hydrate in the form of the minerals trichalcite and rollandite .

Extraction and presentation

Copper (II) arsenate can be obtained by neutralizing solutions of copper (II) sulfate and arsenic (V) oxide with sodium hydroxide .

properties

Copper (II) arsenate is a dichroic blue and olive green solid that is in the form of prisms or tablets. It does not absorb water in air and is easily soluble in hydrochloric acid. It has a monoclinic crystal structure with the space group P 2 ₁ / c (space group no. 14) . In addition, however, two modifications of the compound with the space groups P 2 ₁ / a (No. 14, position 3) and P 1 (No. 2) are known. There is also a tetrahydrate and a pentahydrate. The tetrahydrate is in the form of short green needles; it hydrolyzes in hot water and is soluble in strong acids. It converts to the dihydrate at 110 ° C, to the monohydrate at 250 ° C and to the anhydrate at 410 ° C. The pentahydrate present in thin plates has a hexagonal crystal structure with the P 6 ₃ / m (no. 176) . Template: room group / 14Template: room group / 14.3Template: room group / 2Template: room group / 176

use

Copper (II) arsenate can be used as an insecticide , fungicide and wood preservative, but may be used in different countries, e.g. B. in Germany, are no longer used as pesticides.

Individual evidence

↑ ^a ^b ^c ^d ^e ^f ^g 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. 420 ( limited preview in Google Book search).
↑ ^a ^b ^c Entry on copper arsenates. In: Römpp Online . Georg Thieme Verlag, accessed on February 13, 2016.
^ Entry on arsenic compounds in the GESTIS substance database of the IFA , accessed on February 22, 2019 (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.
^ H. Wayne Richardson: Handbook of Copper Compounds and Applications . CRC Press, 1997, ISBN 978-0-8247-8998-5 , pp. 81 ( limited preview in Google Book search).
↑ Herta Effenberger: On the crystal chemistry of three copper (II) -arsenates: Cu ₃ (AsO ₄ ) ₂ -III, Na ₄ Cu (AsO ₄ ) ₂ , and KCu ₄ (AsO ₄ ) ₃ . In: Monthly magazine for chemistry. 119, 1988, p. 1103, doi : 10.1007 / BF00809262 .

[R._Blachnik-1] ↑ ^a ^b ^c ^d ^e ^f ^g 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. 420 ( limited preview in Google Book search).

[RömppOnline-2] Entry on copper arsenates. In: Römpp Online . Georg Thieme Verlag, accessed on February 13, 2016.

[3] Entry on arsenic compounds in the GESTIS substance database of the IFA , accessed on February 22, 2019 (JavaScript required)

[CLP_100.240.769-4] 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 .

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

[H._Wayne_Richardson-6] H. Wayne Richardson: Handbook of Copper Compounds and Applications . CRC Press, 1997, ISBN 978-0-8247-8998-5 , pp. 81 ( limited preview in Google Book search).

[DOI10.1007/BF00809262-7] Herta Effenberger: On the crystal chemistry of three copper (II) -arsenates: Cu ₃ (AsO ₄ ) ₂ -III, Na ₄ Cu (AsO ₄ ) ₂ , and KCu ₄ (AsO ₄ ) ₃ . In: Monthly magazine for chemistry. 119, 1988, p. 1103, doi : 10.1007 / BF00809262 .