Copper arsenate (Cu
3(AsO
4)
2·4H
2O, or Cu
5H
2(AsO
4)
4·2H
2O), 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
The ammonium cation is a positively-charged polyatomic ion with the chemical formula or . It is formed by the protonation of ammonia (). Ammonium is also a general name for positively charged or protonated substituted amines and quaterna ...
and dilute acids. Its
CAS number
A CAS Registry Number (also referred to as CAS RN or informally CAS Number) is a unique identification number assigned by the Chemical Abstracts Service (CAS), US to every chemical substance described in the open scientific literature. It inclu ...
is or .
Uses
Copper arsenate is an
insecticide
Insecticides are substances used to kill insects. They include ovicides and larvicides used against insect eggs and larvae, respectively. Insecticides are used in agriculture, medicine, industry and by consumers. Insecticides are claimed t ...
used in agriculture. It is also used as a
herbicide
Herbicides (, ), also commonly known as weedkillers, are substances used to control undesired plants, also known as weeds.EPA. February 201Pesticides Industry. Sales and Usage 2006 and 2007: Market Estimates. Summary in press releasMain page f ...
,
fungicide
Fungicides are biocidal chemical compounds or biological organisms used to kill parasitic fungi or their spores. A fungistatic inhibits their growth. Fungi can cause serious damage in agriculture, resulting in critical losses of yield, quality ...
, and a
rodenticide
Rodenticides are chemicals made and sold for the purpose of killing rodents. While commonly referred to as "rat poison", rodenticides are also used to kill mice, squirrels, woodchucks, chipmunks, porcupines, nutria, beavers, and voles. Despi ...
. It is also used as a poison in
slug
Slug, or land slug, is a common name for any apparently shell-less terrestrial gastropod mollusc. The word ''slug'' is also often used as part of the common name of any gastropod mollusc that has no shell, a very reduced shell, or only a ...
baits.
Copper arsenate can also be a misnomer for
copper arsenite
Scheele's Green, also called Schloss Green, is chemically a cupric hydrogen arsenite (also called copper arsenite or acidic copper arsenite), . It is chemically related to Paris Green. Scheele's Green was invented in 1775 by Carl Wilhelm Sche ...
, especially when meant as a
pigment
A pigment is a colored material that is completely or nearly insoluble in water. In contrast, dyes are typically soluble, at least at some stage in their use. Generally dyes are often organic compounds whereas pigments are often inorganic compou ...
.
Natural occurrences
Anhydrous copper arsenate, Cu
3(AsO
4)
2, is found in nature as the mineral lammerite. Copper arsenate tetrahydrate, Cu
3(AsO
4)
2·4H
2O, occurs naturally as the mineral rollandite.
Related compounds
Copper arsenate hydroxide or basic copper arsenate (Cu(OH)AsO
4) is a basic variant with CAS number . It is found naturally as the mineral
olivenite
Olivenite is a copper arsenate mineral, formula Cu2 As O4O H. It crystallizes in the monoclinic system (pseudo-orthorhombic), and is sometimes found in small brilliant crystals of simple prismatic habit terminated by domal faces. More commo ...
. It is used as an insecticide, fungicide, and
miticide
Acaricides are pesticides that kill members of the arachnid subclass ''Acari'', which includes ticks and mites.
Acaricides are used both in medicine and agriculture, although the desired selective toxicity differs between the two fields.
Termino ...
. Its use is banned in Thailand since 2001.
See also
*
Lead arsenate
*
Calcium arsenate
Calcium arsenate is the inorganic compound with the formula Ca3(AsO4)2. A colourless salt, it was originally used as a pesticide and as a germicide. It is highly soluble in water, in contrast to lead arsenate, which makes it more toxic. The minera ...
*
Paris Green (copper acetoarsenite)
*
Chromated copper arsenate Chromated copper arsenate (CCA) is a wood preservative containing compounds of chromium, copper, and arsenic, in various proportions. It is used to impregnate timber and other wood products, especially those intended for outdoor use, in order to pr ...
*
Scheele's Green
Scheele's Green, also called Schloss Green, is chemically a cupric hydrogen arsenite (also called copper arsenite or acidic copper arsenite), . It is chemically related to Paris Green. Scheele's Green was invented in 1775 by Carl Wilhelm Sch ...
(copper arsenite)
References
External links
National Pollutant Inventory - Copper and compounds fact sheet
{{Insecticides
Arsenates
Copper(II) compounds
Inorganic insecticides
Arsenical herbicides
Rodenticides
Fungicides