Protactinium(V) oxide is a chemical compound with the formula Pa2O5. When it is reduced with hydrogen, it forms PaO2. Aristid V. Grosse was first to prepare 2 mg of Pa2O5 in 1927.[1] Pa2O5 does not dissolve in concentrated HNO3, but dissolves in HF and in a HF + H2SO4 mixture and reacts at high temperatures with solid oxides of alkali metal and alkaline earth metals.[2][3]: 195
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IUPAC name
Protactinium(V) oxide
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Identifiers | |
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3D model (JSmol)
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Properties | |
Pa 2O 5 | |
Molar mass | 542.0688 g mol−1 |
Appearance | White, opaque crystals |
Structure | |
cubic | |
Fm-3m, No. 225 | |
Hazards | |
Occupational safety and health (OHS/OSH): | |
Main hazards
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highly toxic, radioactive |
GHS labelling: | |
NFPA 704 (fire diamond) | |
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
Infobox references
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As protactinium(V) oxide, like other protactinium compounds, is radioactive, toxic and very rare, it has very limited technological use. Mixed oxides of Nb, Mg, Ga and Mn, doped with 0.005–0.52% Pa2O5, have been used as high temperature dielectrics (up to 1300 °C) for ceramic capacitors.[3]: 189