Cobalt carbonate

Cobalt(II) carbonate

Names
IUPAC name Cobalt(II) carbonate
Other names Cobaltous carbonate; cobalt(II) salt
Identifiers
CAS Number	513-79-1 N 12602-23-2 (cobalt carbonate hydroxide) N
3D model (Jmol)	Interactive image
ChemSpider	10123 N
ECHA InfoCard	100.007.428
PubChem CID	10565
InChI InChI=1S/CH2O3.Co/c2-1(3)4;/h(H2,2,3,4);/q;+2/p-2 N Key: ZOTKGJBKKKVBJZ-UHFFFAOYSA-L N InChI=1/CH2O3.Co/c2-1(3)4;/h(H2,2,3,4);/q;+2/p-2 Key: ZOTKGJBKKKVBJZ-NUQVWONBAB
SMILES C(=O)([O-])[O-].[Co+2]
Properties
Chemical formula	CoCO3
Appearance	red/ pink crystals (anhydrous) pink, violet, red crystalline powder (hexahydrate)
Density	4.13 g/cm3
Melting point	427 °C (801 °F; 700 K) decomposes before melting to cobalt(II) oxide (anhydrous) 140 °C (284 °F; 413 K) decomposes (hexahydrate)
Solubility in water	negligible
Solubility product (Ksp)	1.0·10−10
Solubility	soluble in acid negligible in alcohol, methyl acetate insoluble in ethanol
Refractive index (nD)	1.855
Structure
Crystal structure	Rhombohedral (anhydrous) Trigonal (hexahydrate)
Thermochemistry
Std molar entropy (So298)	79.9 J/mol·K
Std enthalpy of formation (ΔfHo298)	−722.6 kJ/mol
Gibbs free energy (ΔfG˚)	-651 kJ/mol
Hazards
GHS pictograms
GHS signal word	Warning
GHS hazard statements	H302, H315, H317, H319, H335, H351
GHS precautionary statements	P261, P280, P305+351+338
EU classification (DSD)	Xn
R-phrases	R22, R36/37/38, R40, R43
S-phrases	S26, S36/37
NFPA 704	0 1 0
Lethal dose or concentration (LD, LC):
LD50 (median dose)	640 mg/kg (oral, rats)
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
N  (what is YN ?)
Infobox references

Cobalt(II) carbonate is the inorganic compound with the formula CoCO₃. 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 catalysts. Commercially available pale violet basic cobalt carbonate, with the formula CoCO₃(Co(OH)_x(H₂O)_y (CAS 12069-68-0).

It is prepared by heating cobaltous sulfate with a solution of sodium bicarbonate.

Heating the carbonate, i.e. calcining, proceeds in the usual way:

The resulting Co₃O₄ converts reversibly to CoO at high temperatures. Like most transition metal carbonates, cobalt carbonate is insoluble in water, but is readily attacked by mineral acids:

Cobalt carbonate is a precursor to cobalt carbonyl 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.

The compound is harmful if swallowed, and irritating to eyes and skin.