Cobalt(II) oxide
Cobalt(II) oxide or cobalt monoxide is an inorganic compound that appears as olive-green to red crystals, or as a greyish or black powder.[3] It is used extensively in the ceramics industry as an additive to create blue colored glazes and enamels as well as in the chemical industry for producing cobalt(II) salts.
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| Names | |
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| IUPAC name
Cobalt(II) oxide
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| Other names
Cobaltous oxide
Cobalt monoxide | |
| Identifiers | |
3D model (JSmol)
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| ChemSpider | |
| ECHA InfoCard | 100.013.777 |
| EC Number |
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PubChem CID
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| RTECS number |
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| UN number | 3288 |
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| Properties | |
| CoO | |
| Molar mass | 74.9326 g/mol |
| Appearance | black powder |
| Odor | odorless |
| Density | 6.44 g/cm3 [1] |
| Melting point | 1,933 °C (3,511 °F; 2,206 K) |
| insoluble in water[2] | |
| +4900.0·10−6 cm3/mol | |
| Structure | |
| cubic, cF8 | |
| Fm3m, No. 225 | |
| Hazards | |
| Main hazards | Toxic (T) Harmful (Xn) |
| Safety data sheet | ICSC 1551 |
EU classification (DSD) (outdated)
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 T Xn N
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| R-phrases (outdated) | R22, R43, R50/53 |
| S-phrases (outdated) | (S2), S24, S37, S60, S61 |
| NFPA 704 (fire diamond) | |
| Flash point | Non-flammable |
| Lethal dose or concentration (LD, LC): | |
LD50 (median dose)
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202 mg/kg |
| Related compounds | |
Other anions
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Cobalt(II) sulfide Cobalt(II) hydroxide |
Other cations
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Iron(II) oxide Nickel(II) oxide |
Related compounds
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Cobalt(II,III) oxide Cobalt(III) oxide |
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). | |
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| Infobox references | |
Structure and propertiesEdit
CoO crystals adopt the periclase (rock salt) structure with a lattice constant of 4.2615 Å.[4]
It is antiferromagnetic below 16 °C.[5]
PreparationEdit
Cobalt(II,III) oxide decomposes to cobalt(II) oxide at 950 °C:[6]
- 2 Co3O4 → 6 CoO + O2
Though commercially available, cobalt(II) oxide may be prepared in the laboratory by electrolyzing a solution of cobalt(II) chloride.[7]
CoCl2 + H2O → CoO + H2 + Cl2
It may also be prepared by precipitating the hydroxide, followed by thermal dehydration:
- CoX + 2 KOH → Co(OH)2 + K2X
- Co(OH)2 → CoO + H2O
ReactionsEdit
As can be expected, cobalt(II) oxide reacts with mineral acids to form the corresponding cobalt salts:
- CoO + 2 HX → CoX2 + H2O
ApplicationsEdit
Cobalt(II) oxide has for centuries used as a coloring agent on kiln fired pottery. The additive provides a deep shade of blue named cobalt blue. The band gap (CoO) is around 2.4 eV.[citation needed] It also is used in cobalt blue glass.
See alsoEdit
ReferencesEdit
- ^ Patnaik, Pradyot (2003). Handbook of Inorganic Chemical Compounds. McGraw-Hill. ISBN 0-07-049439-8. Retrieved 2009-06-06.
- ^ Advanced Search – Alfa Aesar – A Johnson Matthey Company Archived 2011-07-19 at the Wayback Machine. Alfa.com. Retrieved on 2011-11-19.
- ^ "Safety (MSDS) data for cobalt oxide". The Physical and Theoretical Chemistry Laboratory, Oxford University. Retrieved 2008-11-11.
- ^ Kannan, R.; Seehra, Mohindar S. (1987). "Percolation effects and magnetic properties of the randomly diluted fcc system CopMg1-pO". Physical Review B. 35 (13): 6847–6853. doi:10.1103/PhysRevB.35.6847.
- ^ Silinsky, P. S.; Seehra, Mohindar S. (1981). "Principal magnetic susceptibilities and uniaxial stress experiments in CoO". Physical Review B. 24: 419–423. doi:10.1103/PhysRevB.24.419.
- ^ US 4389339, James, Leonard E.; Crescentini, Lamberto & Fisher, William B., "Process for making a cobalt oxide catalyst"
- ^ Kern, S. (1876). "Inorganic chemistry". J. Chem. Soc. 29: 880. doi:10.1039/JS8762900876.