Uranium trioxide facts for kids
Quick facts for kids Uranium trioxide |
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| IUPAC name | Uranium trioxide Uranium(VI) oxide |
| Other names | Uranyl oxide Uranic oxide |
| Identifiers | |
| CAS number | |
| Properties | |
| Molecular formula | UO3 |
| Molar mass | 286.29 g/mol |
| Appearance | yellow-orange powder |
| Density | 5.5–8.7 g/cm3 |
| Melting point |
~200–650 °C (decomposes) |
| Solubility in water | Partially soluble |
| Structure | |
| Crystal structure | see text |
| Space group | I41/amd (γ-UO3) |
| Thermochemistry | |
| Std enthalpy of formation ΔfH |
−1230 kJ·mol−1 |
| Standard molar entropy S |
99 J·mol−1·K−1 |
| Hazards | |
| EU classification | Very toxic (T+) Dangerous for the environment (N) |
| NFPA 704 |
0
4
1
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| R-phrases | R26/28, R33, R51/53 |
| S-phrases | (S1/2), S20/21, S45, S61 |
| Flash point | Non-flammable |
| Except where noted otherwise, data are given for materials in their standard state (at 25 °C, 100 kPa) | |
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.
Images for kids
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Methods of forming uranium trioxide
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The calculated geometry of molecular uranium trioxide has C2v symmetry.
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Uranium trioxide Facts for Kids. Kiddle Encyclopedia.