Uranium trioxide
| Names | |
|---|---|
| IUPAC names
Uranium trioxide Uranium(VI) oxide | |
| Other names
Uranyl oxide Uranic oxide | |
| Identifiers | |
3D model (JSmol) |
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| ChemSpider | |
| ECHA InfoCard | 100.014.274 |
| EC Number |
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PubChem CID |
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| UNII | |
CompTox Dashboard (EPA) |
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| Properties | |
| UO3 | |
| Molar mass | 286.29 g/mol |
| Appearance | yellow-orange powder |
| Density | 5.5–8.7 g/cm3 |
| Melting point | ~200–650 °C (decomposes) |
| insoluble | |
| Structure | |
| see text | |
| I41/amd (γ-UO3) | |
| Thermochemistry | |
Std molar entropy (S⦵298) |
99 J·mol−1·K−1 |
Std enthalpy of formation (ΔfH⦵298) |
−1230 kJ·mol−1 |
| Hazards | |
| GHS labelling: | |
| Danger | |
| H300, H330, H373, H411 | |
| NFPA 704 (fire diamond) | |
| Flash point | Non-flammable |
| Safety data sheet (SDS) | External MSDS |
| Related compounds | |
| Uranium dioxide Triuranium octoxide | |
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
Infobox references | |
Uranium trioxide (UO3), also called uranyl oxide, uranium(VI) oxide, and uranic oxide, is the hexavalent oxide of uranium. The solid may be obtained by heating uranyl nitrate to 400 °C. Its most commonly encountered polymorph is amorphous UO3.