Back تریاوکسید اورانیوم AZB Oxid uranový Czech Uran(VI)-oxid German تریاکسید اورانیم FA Uraanitrioksidi Finnish Trioxyde d'uranium French Urán-trioxid Hungarian Triossido di uranio Italian 酸化ウラン(VI) Japanese Trióxido de urânio Portuguese
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| Names | |
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| 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[1] |
Std enthalpy of
formation (ΔfH⦵298) |
−1230 kJ·mol−1[1] |
| Hazards | |
| GHS labelling: | |
  
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| 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).
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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.
- ^ a b Zumdahl SS (2009). Chemical Principles 6th Ed. Houghton Mifflin Company. p. A23. ISBN 978-0-618-94690-7.