Uranium trioxide
Names | |
---|---|
IUPAC names
Uranium trioxide
Uranium(VI) oxide | |
Other names
Uranyl oxide
Uranic oxide | |
Identifiers | |
ECHA InfoCard | 100.014.274 |
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 |
|
R-phrases | R26/28, R33, R51/53 |
S-phrases | (S1/2), S20/21, S45, S61 |
Flash point | Non-flammable |
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 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.
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 | change source]
- ↑ 1.0 1.1 Zumdahl, Steven S. (2009). Chemical Principles 6th Ed. Houghton Mifflin Company. p. A23. ISBN 0-618-94690-X.