Cobalt(II) carbonate is the
inorganic compound with the formula CoCO
3. This reddish paramagnetic solid is an intermediate in the
hydrometallurgical purification of cobalt from its ores. It is an inorganic pigment, and a precursor to
catalyst
Catalysis () is the process of increasing the rate of a chemical reaction by adding a substance known as a catalyst (). Catalysts are not consumed in the reaction and remain unchanged after it. If the reaction is rapid and the catalyst recyc ...
s.
Cobalt(II) carbonate also occurs as the rare red/pink mineral
spherocobaltite.
Preparation and structure
It is prepared by combining solutions cobaltous sulfate and
sodium bicarbonate:
:CoSO
4 + 2 NaHCO
3 → CoCO
3 + Na
2SO
4 + H
2O + CO
2
This reaction is used in the precipitation of cobalt from an extract of its roasted ores.
[
CoCO3 adopts a structure like calcite, consisting of cobalt in an ]octahedral coordination geometry
In chemistry, octahedral molecular geometry, also called square bipyramidal, describes the shape of compounds with six atoms or groups of atoms or ligands symmetrically arranged around a central atom, defining the vertices of an octahedron. The oc ...
.
Reactions
Like most transition metal carbonates, cobalt carbonate is insoluble in water, but is readily attacked by mineral acids:
:CoCO3 + 2 HCl + 5 H2O → o(H2O)6l2 + CO2
It is used to prepare many coordination complexes. The reaction of cobalt(II) carbonate and acetylacetone in the presence of hydrogen peroxide
Hydrogen peroxide is a chemical compound with the formula . In its pure form, it is a very pale blue liquid that is slightly more viscous than water. It is used as an oxidizer, bleaching agent, and antiseptic, usually as a dilute solution (3%â ...
gives tris(acetylacetonato)cobalt(III).
Heating the carbonate proceeds in a typical way for calcining
Calcination refers to thermal treatment of a solid chemical compound (e.g. mixed carbonate ores) whereby the compound is raised to high temperature without melting under restricted supply of ambient oxygen (i.e. gaseous O2 fraction of air), gener ...
, except that the product becomes partially oxidized:
: 6CoCO3 + O2 → 2Co3O4 + 6CO2
The resulting Co3O4 converts reversibly to CoO at high temperatures.
Uses
Cobalt carbonate is a precursor to cobalt carbonyl
Dicobalt octacarbonyl is an organocobalt compound with composition . This metal carbonyl is used as a reagent and catalyst in organometallic chemistry and organic synthesis, and is central to much known organocobalt chemistry. It is the parent me ...
and various cobalt salts. It is a component of dietary supplements since cobalt is an essential element. It is a precursor to blue pottery glazes, famously in the case of Delftware
Delftware or Delft pottery, also known as Delft Blue ( nl, Delfts blauw) or as delf,
is a general term now used for Dutch tin-glazed earthenware, a form of faience. Most of it is blue and white pottery, and the city of Delft in the Netherlands ...
.
Related compounds
At least two cobalt(II) carbonate-hydroxides are known: Co2(CO3)(OH)2 and Co6(CO3)2(OH)8·H2O.habit
A habit (or wont as a humorous and formal term) is a routine of behavior that is repeated regularly and tends to occur subconsciously. to spherocobaltite.
Safety
Toxicity has rarely been observed. Animals, including humans, require trace amounts of cobalt, a component of vitamin B12
Vitamin B12, also known as cobalamin, is a water-soluble vitamin involved in metabolism. It is one of eight B vitamins. It is required by animals, which use it as a cofactor in DNA synthesis, in both fatty acid and amino acid metabolism. ...
.[
]
References
External links
*
{{Cobalt compounds
Cobalt(II) compounds
Carbonates