Cobalt(II) hydroxide

Cobalt(II) hydroxide
	; cobalt(II) hydroxide
Names
	IUPAC name Cobalt(II) hydroxide
	Other names Cobaltous hydroxide, cobalt hydroxide, β-cobalt(II) hydroxide
Identifiers
CAS Number	21041-93-0 ;
3D model (JSmol)	Interactive image;
ChemSpider	8305419 ;
ECHA InfoCard	100.040.136
EC Number	244-166-4;
PubChem CID	10129900;
UNII	51B9AYG60K ;
UN number	3550
CompTox Dashboard (EPA)	DTXSID70894155 ;
	InChI InChI=1S/Co.2H2O/h;21H2/q+2;;/p-2 Key: ASKVAEGIVYSGNY-UHFFFAOYSA-L ; InChI=1/Co.2H2O/h;21H2/q+2;;/p-2 Key: ASKVAEGIVYSGNY-NUQVWONBAS;
	SMILES [Co+2].[OH-].[OH-];
Properties
Chemical formula	Co(OH)2
Molar mass	92.948 g/mol
Appearance	rose-red powder or bluish-green powder
Density	3.597 g/cm3
Melting point	168 °C (334 °F; 441 K) (decomposes)
Solubility in water	3.20 mg/L
Solubility product (Ksp)	1.0×10−15
Solubility	soluble in acids, ammonia; insoluble in dilute alkalis
Structure
Coordination geometry	rhombohedral
Thermochemistry
Std molar; entropy (S⦵298)	79.0 J·mol−1·K−1
Std enthalpy of; formation (ΔfH⦵298)	-539.7 kJ·mol−1
Hazards
	GHS labelling:
Pictograms
Signal word	Warning
Hazard statements	H302, H317, H319, H330, H334, H360, H372
Precautionary statements	P201, P202, P260, P261, P264, P270, P271, P272, P280, P281, P284, P285, P301+P312, P302+P352, P304+P340, P304+P341, P305+P351+P338, P308+P313, P310, P314, P320, P321, P330, P333+P313, P337+P313, P342+P311, P363, P403+P233, P405, P501
NFPA 704 (fire diamond)	1 0 2
Safety data sheet (SDS)	Oxford University
Related compounds
Other anions	Cobalt(II) chloride; Cobalt(II) bromide; Cobalt(II) iodide
Other cations	Iron(II) hydroxide; Nickel(II) hydroxide ; Copper(II) hydroxide
	Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). verify (what is ?) Infobox references

Cobalt(II) hydroxide or cobaltous hydroxide is the inorganic compound with the formula Co(OH)
₂, consisting of divalent cobalt cations Co²⁺
and hydroxide anions OH⁻
. The pure compound, often called the "beta form" (β-Co(OH)
₂) is a pink solid insoluble in water.^[2]^[3]

The name is also applied to a related compound, often called "alpha" or "blue" form (α-Co(OH)
₂), which incorporates other anions in its molecular structure. This compound is blue and rather unstable.^[2]^[3]

Cobalt(II) hydroxide is most used as a drying agent for paints, varnishes, and inks, in the preparation of other cobalt compounds, as a catalyst and in the manufacture of battery electrodes.

^ ^a ^b Lide, David R. (1998). Handbook of Chemistry and Physics (87 ed.). Boca Raton, Florida: CRC Press. p. 513. ISBN 0-8493-0594-2.
^ ^a ^b Lide, David R. (1998). Handbook of Chemistry and Physics (87 ed.). Boca Raton, Florida: CRC Press. p. 454. ISBN 0-8493-0594-2.
^ ^a ^b Xiaohe Liu, Ran Yi, Ning Zhang, Rongrong Shi, Xingguo Li, and Guanzhou Qiu (2008): "Cobalt hydroxide nanosheets and their thermal decomposition to cobalt oxide nanorings". Chemistry: An Asian Journal, volume 3, issue 4, pages 732-738. doi:10.1002/asia.200700264

[hand2-1] Lide, David R. (1998). Handbook of Chemistry and Physics (87 ed.). Boca Raton, Florida: CRC Press. p. 513. ISBN 0-8493-0594-2.

[hand-2] Lide, David R. (1998). Handbook of Chemistry and Physics (87 ed.). Boca Raton, Florida: CRC Press. p. 454. ISBN 0-8493-0594-2.

[Liu-3] Xiaohe Liu, Ran Yi, Ning Zhang, Rongrong Shi, Xingguo Li, and Guanzhou Qiu (2008): "Cobalt hydroxide nanosheets and their thermal decomposition to cobalt oxide nanorings". Chemistry: An Asian Journal, volume 3, issue 4, pages 732-738. doi:10.1002/asia.200700264

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