Cobalt(II) hydroxide
cobalt(II) hydroxide | |
| Names | |
|---|---|
| IUPAC name
Cobalt(II) hydroxide | |
| Other names
Cobaltous hydroxide, cobalt hydroxide, β-cobalt(II) hydroxide | |
| Identifiers | |
3D model (JSmol) |
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| ChemSpider | |
| ECHA InfoCard | 100.040.136 |
| EC Number |
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PubChem CID |
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| UNII | |
| UN number | 3550 |
CompTox Dashboard (EPA) |
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| Properties | |
| Co(OH)2 | |
| Molar mass | 92.9468 g/mol |
| Appearance | rose-red powder or bluish-green powder |
| Density | 3.597 g/cm3 |
| Melting point | 168 °C (334 °F; 441 K) (decomposes) |
| 3.20 mg/L | |
Solubility product (Ksp) |
1.0×10−15 |
| Solubility | soluble in acids, ammonia; insoluble in dilute alkalis |
| Structure | |
| 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: | |
| Warning | |
| H302, H317, H319, H330, H334, H360, H372 | |
| 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) | |
| 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).
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.
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.
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.