Cobalt(II) oxide

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Cobalt(II) oxide
Cobalt(II) oxide
Identifiers
CAS number 1307-96-6 YesY
PubChem 9942118
ChemSpider 8117730 YesY
EC number 215-154-6
UN number 3288
RTECS number GG2800000
Jmol-3D images Image 1
Image 2
Properties
Molecular formula 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)
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) hydroxide
Other cations Iron(II) oxide
Nickel(II) oxide
Related compounds Cobalt(II,III) oxide
Cobalt(III) oxide
Except where noted otherwise, data are given for materials in their standard state (at 25 °C (77 °F), 100 kPa)
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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.

Structure and properties[edit]

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[edit]

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[edit]

As can be expected, cobalt(II) oxide reacts with mineral acids to form the corresponding cobalt salts:

CoO + 2 HX → CoX2 + H2O

Applications[edit]

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[edit]

  1. ^ Patnaik, Pradyot (2003). Handbook of Inorganic Chemical Compounds. McGraw-Hill. ISBN 0-07-049439-8. Retrieved 2009-06-06. 
  2. ^ Advanced Search – Alfa Aesar – A Johnson Matthey Company. Alfa.com. Retrieved on 2011-11-19.
  3. ^ "Safety (MSDS) data for cobalt oxide". The Physical and Theoretical Chemistry Laboratory, Oxford University. Retrieved 2008-11-11. 
  4. ^ 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. 
  5. ^ 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. 
  6. ^ US 4389339, James, Leonard E.; Crescentini, Lamberto & Fisher, William B., "Process for making a cobalt oxide catalyst" 
  7. ^ Kern, S. (1876). J. Chem. Soc.: 880.