Cobalt(III) oxide
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IUPAC name
cobalt(III) oxide, dicobalt trioxide
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Other names
cobaltic oxide, cobalt sesquioxide
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Identifiers | |
3D model (
JSmol ) |
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ECHA InfoCard
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100.013.779 |
EC Number |
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PubChem CID
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RTECS number
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CompTox Dashboard (EPA)
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Properties | |
Co2O3 | |
Molar mass | 165.8646 g/mol |
Appearance | red powder |
Density | 5.18 g/cm3 [2] |
Melting point | 895[3] °C (1,643 °F; 1,168 K) |
negligible | |
+4560.0·10−6 cm3/mol | |
Structure | |
Corundum, hR30 | |
R3c, No. 167 | |
Thermochemistry | |
Std enthalpy of (ΔfH⦵298)formation |
-577 kJ/mol |
Hazards | |
Occupational safety and health (OHS/OSH): | |
Main hazards
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toxic |
GHS labelling: | |
Warning | |
H302, H317, H351, H410 | |
P280 | |
NFPA 704 (fire diamond) | |
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
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Cobalt(III) oxide is the inorganic compound with the formula of Co2O3. Although only two oxides of cobalt are well characterized, CoO and Co3O4,[4] procedures claiming to give Co2O3 have been described. Thus treatment of Co(II) salts such as cobalt(II) sulfate with an aqueous solution of sodium hypochlorite (also known as bleach) gives a black solid:[5][6]
- 2CoSO4 + 4NaOH + NaOCl → Co2O3 + 2Na2SO4 + NaCl
Some formulations of the catalyst hopcalite contain "Co2O3".
Some studies have been unable to synthesize the compound, and report that it is theoretically unstable.[7]
It is soluble in cold diluted sulfuric acid and produces Co2[SO4]3, which is blue in aqueous solution.
- Co2O3 + 3H2SO4 → Co2[SO4]3 + 3H2O
Cobalt(III) ion is a strong
oxidizer in acidic solution, its standard electrode potential is +1.84V in this situation.[8]
See also
- Cobalt Oxide Nanoparticles
References
- ^ Sigma-Aldrich product page
- ISBN 0-8493-0487-3.
- ^ "1308-04-9 CAS MSDS (COBALT(III) OXIDE BLACK) Melting Point Boiling Point Density CAS Chemical Properties".
- ISBN 978-0-08-037941-8.
- ^ Handbook of Preparative Inorganic Chemistry, 2nd Ed. Edited by G. Brauer, Academic Press, 1963, NY. p. 1675.
- ISSN 0863-1778.
- PMID 33225132.
- ISBN 9787040115833.