Uranium trioxide

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Uranium trioxide
Names
IUPAC names
Uranium trioxide
Uranium(VI) oxide
Other names
Uranyl oxide
Uranic oxide
Identifiers
ECHA InfoCard 100.014.274
PubChem {{{value}}}
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
ΔfHo298
−1230 kJ·mol−1[1]
Standard molar
entropy
So298
99 J·mol−1·K−1[1]
Hazards
EU classification Very toxic (T+)
Dangerous for the environment (N)
NFPA 704

NFPA 704.svg

0
4
1
 
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).
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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. 1.0 1.1 Zumdahl, Steven S. (2009). Chemical Principles 6th Ed. Houghton Mifflin Company. p. A23. ISBN 0-618-94690-X.