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Names | |
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Other names | |
Identifiers | |
3D model (JSmol)
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ChEBI | |
ChemSpider | |
ECHA InfoCard | 100.013.783 |
EC Number |
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11116 | |
PubChem CID
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RTECS number |
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UNII | |
UN number | 3077 |
CompTox Dashboard (EPA)
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Properties | |
Cr2O3 | |
Molar mass | 151.9904 g/mol |
Appearance | light to dark green, fine crystals |
Density | 5.22 g/cm3 |
Melting point | 2,435 °C (4,415 °F; 2,708 K) |
Boiling point | 4,000 °C (7,230 °F; 4,270 K) |
insoluble | |
Solubility in alcohol | insoluble in alcohol, acetone, acids |
+1960.0×10−6 cm3/mol | |
Refractive index (nD)
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2.551 |
Structure[1] | |
Corundum | |
R3c (No. 167) | |
a = 495 pm, c = 1358 pm
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Thermochemistry | |
Std molar
entropy (S⦵298) |
81 J·mol−1·K−1 |
Std enthalpy of
formation (ΔfH⦵298) |
−1128 kJ·mol−1 |
Hazards | |
GHS labelling: | |
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Danger | |
H302, H317, H319, H360 | |
P201, P202, P261, P264, P270, P272, P280, P281, P301+P312, P302+P352, P305+P351+P338, P308+P313, P321, P330, P333+P313, P337+P313, P363, P405, P501 | |
NIOSH (US health exposure limits): | |
PEL (Permissible)
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TWA 1 mg/m3[2] |
REL (Recommended)
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TWA 0.5 mg/m3[2] |
IDLH (Immediate danger)
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250 mg/m3[2] |
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
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Chromium(III) oxide (or chromia) is an inorganic compound with the formula Cr
2O
3. It is one of the principal oxides of chromium and is used as a pigment. In nature, it occurs as the rare mineral eskolaite.