Names | |
---|---|
IUPAC name
Cobalt(III) hydroxide
| |
Other names
Cobaltic hydroxide
| |
Identifiers | |
3D model (
JSmol)
|
|
ChemSpider | |
ECHA InfoCard | 100.013.776 |
EC Number |
|
PubChem
CID
|
|
UNII | |
CompTox Dashboard (
EPA)
|
|
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Properties | |
Co(OH)3 | |
Molar mass | 109.95522 g |
Appearance | brown-black or dark green powder |
Hazards | |
GHS labelling: | |
Danger | |
H319, H334, H413 | |
P261, P264, P273, P280, P285, P304+P341, P305+P351+P338, P337+P313, P342+P311, P501 | |
Except where otherwise noted, data are given for materials in their
standard state (at 25 °C [77 °F], 100 kPa).
|
Cobalt(III) hydroxide or cobaltic hydroxide is a
chemical compound with formula Co(OH)
3 or H
3CoO
3. It is an
ionic compound, with
trivalent
cobalt
cations Co3+
and
hydroxyl
anions OH−
.
The compound is known in two structurally different forms, "brownish-black" and "green". The brownish-black form is a stable solid and can be prepared by reaction of water solutions of cobalt(II) chloride and sodium hydroxide, followed by oxidation with ozone. [1]
The green form, formerly thought to be cobalt(II) peroxide, apparently requires carbon dioxide as a catalyst. It can be prepared by adding hydrogen peroxide to a solution of cobalt(II) chloride in 96% ethanol at –30 to –35°C, then adding a 15% solution of sodium carbonate in water with intense stirring. The resulting dark green powder is fairly stable at liquid nitrogen temperature, but at room temperature it turns dark brown within a few days. [2]
As of 2020, Cobalt(III) hydroxide is unknown among the known mineral species. However, heterogenite, CoO(OH), is known. [3] [4]