Uranium trioxide
oxide of uranium
Uranium trioxide (UO3), also called uranyl oxide, uranium(VI) oxide, and uranic oxide, is an oxide of uranium. UO3 is a hexavalent oxide, which means that the uranium in the compound has an oxidation state of +6. It can be formed by heating uranyl nitrate to 400 °C.
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| Names | ||
|---|---|---|
| IUPAC names
Uranium trioxide
Uranium(VI) oxide | ||
| Other names
Uranyl oxide
Uranic oxide | ||
| Identifiers | ||
| ECHA InfoCard | 100.014.274 | |
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) | |
| Partially soluble | ||
| Structure | ||
| see text | ||
| I41/amd (γ-UO3) | ||
| Thermochemistry | ||
| Std enthalpy of formation ΔfH |
−1230 kJ·mol−1[1] | |
| Standard molar entropy S |
99 J·mol−1·K−1[1] | |
| Hazards | ||
| EU classification | Very toxic (T+) Dangerous for the environment (N) | |
| NFPA 704 |
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| R-phrases | R26/28, R33, R51/53 | |
| S-phrases | (S1/2), S20/21, S45, S61 | |
| Flash point | Non-flammable | |
| Related compounds | ||
| Related {{{label}}} | {{{value}}} | |
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). | ||
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| Infobox references | ||
UO3 is a poisonous and slightly radioactive substance. It can be harmful if it is breathed in, ingested, or makes contact with skin.
References
change- ↑ 1.0 1.1 Zumdahl, Steven S. (2009). Chemical Principles 6th Ed. Houghton Mifflin Company. p. A23. ISBN 978-0-618-94690-7.
