Formula Cu3(AsO4)2 Density 5.2 g/cm³ Classification Arsenates | Molar mass 468.48 g/mol Melting point 1,100 °C | |
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Appearance blue or bluish green powder | ||
Copper arsenate (Cu3(AsO4)2.4H2O, or Cu5H2(AsO4)4.2H2O), also called copper orthoarsenate, tricopper arsenate, cupric arsenate, or tricopper orthoarsenate, is a blue or bluish-green powder insoluble in water and alcohol and soluble in aqueous ammonium and dilute acids. Its CAS number is 7778-41-8 or 10103-61-4.
Contents
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.
Copper arsenate can also be a misnomer for copper arsenite, especially when meant as a pigment.
Natural occurrences
Anhydrous copper arsenate, Cu3(AsO4)2, is found in nature as the mineral lammerite. Copper arsenate tetrahydrate, Cu3(AsO4)2.4H2O, occurs naturally as the mineral rollandite.
Related compounds
Copper arsenate hydroxide or basic copper arsenate (Cu(OH)AsO4) is a basic variant with CAS number 16102-92-4. It is found naturally as the mineral olivenite. It is used as an insecticide, fungicide, and miticide. Its use is banned in Thailand since 2001.