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.
Names | |
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IUPAC name
Cobalt(II) oxide | |
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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UNII | |
UN number | 3288 |
CompTox Dashboard (EPA) |
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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 | |
Safety data sheet | ICSC 1551 |
GHS pictograms | |
GHS Signal word | Warning |
GHS hazard statements |
H302, H317, H400, H410 |
P260, P280, P284, P301+310+330, P304+340+310, P342+311, P403+233 | |
NFPA 704 (fire diamond) | |
Flash point | Non-flammable |
Lethal dose or concentration (LD, LC): | |
LD50 (median dose) |
202 mg/kg |
Related compounds | |
Other anions |
Cobalt(II) sulfide Cobalt(II) hydroxide |
Other cations |
Iron(II) oxide Nickel(II) oxide |
Related compounds |
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). | |
Infobox references | |
Structure and properties
CoO crystals adopt the periclase (rock salt) structure with a lattice constant of 4.2615 Å.[4]
It is antiferromagnetic below 16 °C.[5]
Preparation
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
Reactions
As can be expected, cobalt(II) oxide reacts with mineral acids to form the corresponding cobalt salts:
- CoO + 2 HX → CoX2 + H2O
Applications
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. It also is used in cobalt blue glass.
See also
- Cobalt oxide nanoparticles
- Cobalt
- Cobalt(II,III) oxide
References
- 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.