Copper(II) arsenate

Copper(II) arsenate
Names
IUPAC name
Copper(II) arsenate
Other names
  • Copper arsenate
  • Copper orthoarsenate
  • Cupric arsenate
  • Tricopper arsenate
  • Tricopper orthoarsenate
Identifiers
3D model (JSmol)
ChemSpider
UNII
  • InChI=1S/2AsH3O4.3Cu/c2*2-1(3,4)5;;;/h2*(H3,2,3,4,5);;;/q;;3*+2/p-6 checkY
    Key: RKYSWCFUYJGIQA-UHFFFAOYSA-H checkY
  • InChI=1/2AsH3O4.3Cu/c2*2-1(3,4)5;;;/h2*(H3,2,3,4,5);;;/q;;3*+2/p-6
    Key: RKYSWCFUYJGIQA-CYFPFDDLAM
  • [Cu+2].[Cu+2].[Cu+2].[O-][As]([O-])(=O)[O-].[O-][As]([O-])([O-])=O
Properties
Cu3(AsO4)2
Molar mass 468.48 g/mol
Appearance blue or bluish green solid
Density 5.2 g/cm3
Melting point 1,100 °C (2,010 °F; 1,370 K)
insoluble
7.95×10−36
Solubility insoluble in alcohol
soluble in ammonia solution, dilute acids
Structure
monoclinic
P21/c
a = 6.327 Å, b = 8.642 Å, c = 11.313 Å
α = 92.04°, β = 90°, γ = 90°
4 units per cell
Hazards
GHS labelling:
GHS07: Exclamation markGHS08: Health hazard
Danger
H319, H350, H361, H370, H372
P203, P260, P264, P264+P265, P270, P280, P305+P351+P338, P308+P316, P318, P319, P321, P337+P317, P405, P501
NIOSH (US health exposure limits):
PEL (Permissible)
 TWA 1 mg/m3 (as Cu)
REL (Recommended)
 TWA 1 mg/m3 (as Cu)
IDLH (Immediate danger)
 TWA 100 mg/m3 (as Cu)
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
checkY verify (what is checkYX markN ?)

Copper arsenate is an inorganic compound with the chemical formula Cu3(AsO4)2·nH2O (n=0,4). It is a blue or bluish-green solid, forming monoclinic crystals.

Occurrence

Anhydrous copper arsenate (Cu3(AsO4)2) is found in nature as the mineral lammerite. The tetrahydrate (Cu3(AsO4)2·4H2O) occurs naturally as the mineral rollandite.

Preparation

Copper arsenate can be prepared by reacting disodium hydrogen arsenate and copper(II) chloride in aqueous solution.

Uses

Copper arsenate is an insecticide used in agriculture. It is also used as a herbicide, fungicide, and a rodenticide. It is also used as a poison in slug baits.

Basic copper arsenates with the formulas Cu2(OH)AsO4 and Cu3(AsO4)(OH)3 have been observed. The former is found naturally as the mineral olivenite.

See also

References

  1. ↑ John Rumble (June 18, 2018). CRC Handbook of Chemistry and Physics (99 ed.). CRC Press. pp. 5–188. ISBN 978-1138561632.
  2. 1 2 Poulsen, Sandra J.; Calvo, C. (1968-03-15). "Crystal structure of Cu3(AsO4)2". Canadian Journal of Chemistry. 46 (6): 917–927. doi:10.1139/v68-153. ISSN 0008-4042.
  3. ↑ PubChem. "Copper Arsenate". pubchem.ncbi.nlm.nih.gov. Retrieved 2026-02-18.
  4. 1 2 3 "#0150". NIOSH Pocket Guide to Chemical Hazards. National Institute for Occupational Safety and Health.
  5. ↑ Hawthorne, F. C. (1986). "Lammerite, Cu3(AsO4)2, a modulated close-packed structure" (PDF). American Mineralogist. 71: 206–209.
  6. ↑ Sarp, H.; Černý, R. (2000). "Rollandite, Cu3(AsO4)2·4H2O, a new mineral". Eur. J. Mineral. 12: 1045–1050. doi:10.1127/0935-1221/2000/0012-1045.
  7. ↑ US EPA, OCSPP (2014-01-16). "Chromated Arsenicals (CCA)". www.epa.gov. Retrieved 2026-10-19.
  8. ↑ Nelson, Hanna; Shchukarev, Andrey; Sjöberg, Staffan; Lövgren, Lars (2011-05-01). "Composition and solubility of precipitated copper(II) arsenates". Applied Geochemistry. 26 (5): 696–704. doi:10.1016/j.apgeochem.2011.01.028. ISSN 0883-2927.