Identification | Back Directory | [Name]
COBALT(III) OXIDE BLACK | [CAS]
1308-04-9 | [Synonyms]
c.i.77323 COBALT BLACK dicobaltoxide cobalttrioxide Cobolt-3-oxide Cobalt(Ⅲ)oxide COBALTIC OXIDE cobaltperoxide cobalt(3+)oxide cobalitic oxide Cabalt trioxide Cobalt(Ⅱ,Ⅲ)oxide dicobalttrioxide cobalt(iii)oxide cobaltsesqioxide COBALT(2,3) OXIDE COBALT TETRAOXIDE BLACK COBALT OXIDE COBALT SESQUIOXIDE COBALT OXIDE, GRAY COBALT(+2,+3)OXIDE cobaltoxide(co2o3) BLACKCOBALTICOXIDE COBALTIC TETRAOXIDE COBALT(II,III) OXIDE COBALT(III) OXIDE BL COBALT(III) OXIDE BLACK Cobaltic oxide monohydrate COBALT(II)-COBALT(III)-OXIDE COBALT(III) OXIDE BLACK, PURE COBALT(III) OXIDE R. G., FOR THE DETERMI NATION OF SULFUR | [EINECS(EC#)]
215-157-2 | [Molecular Formula]
Co2O3 | [MDL Number]
MFCD00036266 | [MOL File]
1308-04-9.mol | [Molecular Weight]
165.86 |
Chemical Properties | Back Directory | [Definition]
Sometimes incorrectly called cobalt peroxide. | [Appearance]
Steel-gray or black powder.Soluble in concentrated acids; insoluble in water. | [Melting point ]
895 °C (dec.)(lit.)
| [density ]
6.11 g/mL at 25 °C(lit.)
| [storage temp. ]
Inert atmosphere,Room Temperature | [solubility ]
insoluble in H2O; soluble in concentrated acid solutions | [form ]
powder
| [color ]
gray-black | [Water Solubility ]
insoluble H2O; soluble conc acids [HAW93] | [Uses]
Pigment, coloring enamels, glazing pottery. | [EPA Substance Registry System]
Cobalt oxide (Co2O3) (1308-04-9) |
Hazard Information | Back Directory | [Chemical Properties]
Steel-gray or black powder.Soluble in concentrated acids; insoluble in water. | [Description]
Neither the oxide Co2O3 nor the hydroxide Co(OH)3 is definitely established. The oxidation of cobalt(II) hydroxide in aqueous suspension with, for example, peroxides, or the destruction of a cobalt(III) complex with alkali gives a brown or black powder Co2O3.aq which upon drying at 150° yields the monohydrate Co2O3.H2O; this is probably best formulated as CoO(OH). When heated further in attempts to dehydrate it, the "monohydrate" begins to evolve oxygen (as well as water) at 300° with the formation of black Co3O4. When heated to 100° in air cobalt(II) hydroxide is converted to dark brown CoO(OH). | [Physical properties]
Grayish black powder; density 5.18 g/cm3; decomposes at 895°C; insoluble in water; soluble in concentrated mineral acids. |
Safety Data | Back Directory | [Hazard Codes ]
Xn | [Risk Statements ]
36/37/38-40-43-22 | [Safety Statements ]
26-36/37/39-36/37 | [WGK Germany ]
1
| [RTECS ]
GG2500000
| [Safety Profile]
: Moderately toxic by
intraperitoneal and subcutaneous routes.
Questionable carcinogen. Violent reaction
with hydrogen peroxide. The oxide increases
the sensitivity of nitroalkanes (e.g.,
nitromethane, nitroethane, and 1
nitropropane) to heat or detonation. See
also COBALT COMPOUNDS. | [Toxicity]
mouse,LD50,subcutaneous,2064mg/kg (2064mg/kg),Zhurnal Vsesoyuznogo Khimicheskogo Obshchestva im. D.I. Mendeleeva. Journal of the D.I. Mendeleeva All-Union Chemical Society. Vol. 19, Pg. 186, 1974. |
Questions And Answer | Back Directory | [Uses]
COBALT(III) OXIDE BLACK is used as a pigment; for glazing porcelain and pottery; and for coloring enamels.
| [Preparation]
COBALT(III) OXIDE BLACK is prepared by heating cobalt compounds at low temperatures in air.
| [Reactions]
Heating with hydrogen, carbon or carbon monoxide reduces the oxide to cobalt metal.
Co2O3 + 3H2→ 2Co + 3H2O
Co2O3 + 3CO→ 2Co + 3CO
2Co2O3 + 3C→ 4Co + 3CO2
Strong heating in air converts cobalt(III) oxide to tricobalt tetroxide.
Reactions with mineral acids produce their Co3+ salts:
Co2O3 + 6HCl → 2CoCl3 + 3H2O
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