- Cobalt(II) oxide
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Cobalt(II) oxide 
Cobalt(II) oxideOther namesCobaltous oxide
Cobalt monoxideIdentifiers CAS number 1307-96-6 
PubChem 9942118 ChemSpider 8117730 EC number 215-154-6 UN number 3288 RTECS number GG2800000 Jmol-3D images Image 1
Image 2- [Co]=O
[Co+2].[O-2]
- InChI=1S/Co.O/q+2;-2
Key: IUYLTEAJCNAMJK-UHFFFAOYSA-N
InChI=1/Co.O/rCoO/c1-2
Key: IVMYJDGYRUAWML-NNYFCMOLAO
InChI=1/Co.O/q+2;-2
Key: IUYLTEAJCNAMJK-UHFFFAOYAY
Properties Molecular formula CoO Molar mass 74.9326 g/mol Appearance black powder Odor odorless Density 6.44 g/cm3 [1] Melting point 1933 °C, 2206 K, 3511 °F
Solubility in water insoluble in water[2] Structure Crystal structure cubic, cF8 Space group Fm3m, No. 225 Hazards MSDS ICSC 1551 EU Index 027-002-00-4 EU classification Harmful (Xn)
Dangerous for the environment (N)R-phrases R22, R43, R50/53 S-phrases (S2), S24, S37, S60, S61 Flash point Non-flammable LD50 202 mg/kg Related compounds Other anions Cobalt(II) sulfide
Cobalt(II) hydroxideOther cations Iron(II) oxide
Nickel(II) oxideRelated compounds Cobalt(II,III) oxide
Cobalt(III) oxide
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Except where noted otherwise, data are given for materials in their standard state (at 25 °C, 100 kPa)Infobox references 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.
Contents
Structure and properties
CoO crystals adopt the periclase (rock salt) structure with a lattice constant of 4.2615Å[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 decomposition:
- CoX + 2 NaOH → Co(OH)2 + Na2X
- 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.
References
- ^ Patnaik, Pradyot (2003). Handbook of Inorganic Chemical Compounds. McGraw-Hill. ISBN 0070494398. http://books.google.com/?id=Xqj-TTzkvTEC&pg=PA119. Retrieved 2009-06-06.
- ^ http://www.alfa.com/content/msds/german/44354.pdf
- ^ "Safety (MSDS) data for cobalt oxide". The Physical and Theoretical Chemistry Laboratory, Oxford University. http://msds.chem.ox.ac.uk/CO/cobalt_oxide.html. 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. 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. doi:10.1103/PhysRevB.24.419.
- ^ Process for making a cobalt oxide catalyst, James, Leonard E. (Richmond, VA) Crescentini, Lamberto (Chester, VA) Fisher, William B. (Chester, VA) 1983. http://www.freepatentsonline.com/4389339.html
- ^ Kern, S.; J. Chem. Soc.; 1876. Part 1. p880.
Cobalt compounds Categories:- Cobalt compounds
- Oxides
- [Co]=O
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