2431. Cobaltic Oxide Monohydrate

Nomenclature

CAS number: 12016-80-7
Cobalt hydroxide oxide; cobaltic hydroxide.
CoHO2; mol wt 91.94.
Co 64.10%, H 1.10%, O 34.80%.
CoO(OH).

Description and references

Alternate formula Co2O3.H2O. Prepn: Glemser in Handbook of Preparative Inorganic Chemistry vol 2, G. Brauer, Ed. (Academic Press, New York, 2nd ed., 1965) pp 1520-1521; Schrader, Petzold, Z. Anorg. Allg. Chem. 353, 186 (1967). Existence of anhydrous cobaltic oxide (Co2O3) has not been established: Pagel et al., J. Am. Chem. Soc. 57, 2552 (1935); Nicholls in Comprehensive Inorganic Chemistry vol 3, J. C. Bailar, Jr. et al., Eds. (Pergamon Press, Oxford, 1973) p 1096. See also de Bie, Doyen, Cobalt 15, 3 (1962). Structure: Schrader, Petzold, loc. cit.; Delaplane et al., J. Chem. Phys. 50, 1920 (1969).

Properties

Dark-brown to black powder; hexagonal crystal structure. Converted to Co3O4 on heating to 148-150° in a vacuum. Practically insol in water. Sol in HCl, evolving Cl2; sol in HNO3, H2SO4.

Use

Oxidation catalysts, in separation of cobalt from nickel.