Basic copper carbonate
Basic copper carbonate is a chemical compound, more properly called copper(II) carbonate hydroxide. It is an ionic compound (a salt) consisting of the ions copper(II) Cu2+
, carbonate CO2−
3, and hydroxide OH−
.
Space-filling model of the formula unit of basic copper carbonate | |
Names | |
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IUPAC name
Dicopper carbonate dihydroxide | |
Other names
copper carbonate hydroxide, cupric carbonate, copper carbonate, Greenium | |
Identifiers | |
3D model (JSmol) |
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ChemSpider | |
ECHA InfoCard | 100.031.909 |
PubChem CID |
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UNII | |
CompTox Dashboard (EPA) |
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Properties | |
Cu2(OH)2CO3 | |
Molar mass | 221.114 g/mol |
Appearance | green powder |
Density | 4 g/cm3 |
Melting point | 200 °C (392 °F; 473 K) |
Boiling point | 290 °C (554 °F; 563 K) decomposes |
insoluble | |
Solubility product (Ksp) |
7.08·10−9 |
Thermochemistry | |
Std molar entropy (S⦵298) |
88 J/mol·K |
Std enthalpy of formation (ΔfH⦵298) |
−595 kJ/mol |
Hazards | |
GHS labelling: | |
Warning | |
H302, H315, H319, H335 | |
P261, P305+P351+P338 | |
Lethal dose or concentration (LD, LC): | |
LD50 (median dose) |
159 mg/kg (rat, oral) |
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) |
Safety data sheet (SDS) | Oxford MSDS |
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
Infobox references |
The name most commonly refers to the compound with formula Cu
2CO
3(OH)2. It is a green crystalline solid that occurs in nature as the mineral malachite. It has been used since antiquity as a pigment, and it is still used as such in artist paints, sometimes called verditer, green bice, or mountain green.
Sometimes the name is used for Cu
3(CO
3)2(OH)2, a blue crystalline solid also known as the mineral azurite. It too has been used as pigment, sometimes under the name mountain blue or blue verditer.
Both malachite and azurite can be found in the verdigris patina that is found on weathered brass, bronze, and copper. The composition of the patina can vary, in a maritime environment depending on the environment a basic chloride may be present, in an urban environment basic sulfates may be present.
This compound is often improperly called (even in chemistry articles) copper carbonate, cupric carbonate, and similar names. The true (neutral) copper(II) carbonate CuCO3 is not known to occur naturally. It is decomposed by water or moisture from the air, and was synthesized only in 1973 by high temperature and very high pressures.