Cobalt(II,III) oxide

Cobalt(II,III) oxide[1]
IUPAC name
cobalt(II) dicobalt(III) oxide
Other names
cobalt oxide, cobalt(II,III) oxide, cobaltosic oxide, tricobalt tetroxide
1308-06-1 YesY
3D model (Jmol) Interactive image
ChemSpider 9826389 YesY
ECHA InfoCard 100.013.780
PubChem 11651651
RTECS number GG2500000


Molar mass 240.80 g/mol
Appearance black solid
Density 6.11 g/cm3
Melting point 895 °C (1,643 °F; 1,168 K)
Boiling point 900 °C (1,650 °F; 1,170 K) (decomposes)
Solubility soluble in acids and alkalis
R-phrases R40 R41 R42 R43
S-phrases S36/37
NFPA 704
Flammability code 0: Will not burn. E.g., water Health code 2: Intense or continued but not chronic exposure could cause temporary incapacitation or possible residual injury. E.g., chloroform Reactivity code 0: Normally stable, even under fire exposure conditions, and is not reactive with water. E.g., liquid nitrogen Special hazards (white): no codeNFPA 704 four-colored diamond
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
N verify (what is YesYN ?)
Infobox references

Cobalt(II,III) oxide is inorganic compound with the formula Co3O4. It is one of two well characterized cobalt oxides. It is a black antiferromagnetic solid. As a mixed valence compound, its formula is sometimes written as CoIICoIII2O4 and sometimes as CoOCo2O3.[2]


Co3O4 adopts the normal spinel structure, with Co2+ ions in tetrahedral interstices and Co3+ ions in the octahedral interstices of the cubic close-packed lattice of oxide anions.[2]

tetrahedral coordination geometry of Co(II)distorted octahedral coordination geometry of Co(III)distorted tetrahedral coordination geometry of O


Cobalt(II) oxide, CoO, converts to Co3O4 if heated to around 600-700 °C in air.[3] Above 900 °C, CoO is stable.[3][4] These reaction are described by the following equilibrium:

2 Co3O4 6 CoO + O2


This inorganic compound is currently utilized in the process of artificial photosynthesis.


Cobalt compounds are potentially poisonous in large amounts.[5]

See also


  1. Sigma-Aldrich product page
  2. 1 2 Greenwood, Norman N.; Earnshaw, Alan (1997). Chemistry of the Elements (2nd ed.). Butterworth-Heinemann. p. 1118. ISBN 0-08-037941-9.
  3. 1 2 Greenwood, Norman N.; Earnshaw, Alan (1997). Chemistry of the Elements (2nd ed.). Butterworth-Heinemann. p. 1118. ISBN 0-08-037941-9.
  4. Handbook of Preparative Inorganic Chemistry, 2nd Ed. Edited by G. Brauer, Academic Press, 1963, NY. p. 1520.
  5. MSDS
This article is issued from Wikipedia - version of the 9/13/2016. The text is available under the Creative Commons Attribution/Share Alike but additional terms may apply for the media files.