Neptunium(VII) oxide-hydroxide

Neptunium(VII) oxide-hydroxide is a chemical compound which has neptunium in its highest oxidation state of +7. This compound reacts with basic salts such as potassium hydroxide to form neptunates (NpO53-) and water.[1]

Neptunium(VII) oxide-hydroxide
Names
Other names
Neptunyl hydroxide
Identifiers
3D model (JSmol)
  • InChI=1S/Np.3H2O.2O/h;3*1H2;;/q+3;;;;;/p-3
    Key: QJJOKRDJFDRNCY-UHFFFAOYSA-K
  • [Np+3](=O)=O.[OH-].[OH-].[OH-]
Properties
NpO2(OH)3
Molar mass 320.02 g/mol
Appearance Black solid
10 mg/l
Solubility Soluble in nitric acid and 1 M potassium hydroxide
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
NpO2(OH)3 + 3KOH → K3NpO5 + 3H2O

Neptunium(VII) oxide-hydroxide is stable in an alkaline solution, however, it is slowly reduced to Np(VI) in an acidic solution. In water, it forms a greenish solution.[1] This compound decomposes slowly to an oxidized solid.[2]

Production

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Neptunium(VII) oxide-hydroxide is produced by the oxidation of Np(VI) in alkaline solution with ozone, then neutralized with nitric acid to precipitate out the neptunium(VII) oxide-hydroxide.

References

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  1. ^ a b V.I.Spitsyn; A.D.Gelman; N.N.Krot; M.P.Mefodiyeva; F.A.Zakharova; Yu.A.Komkov; V.P.ShilovI.; V.Smirnova (1968). "Heptavalent state of neptunium and plutonium". Journal of Inorganic and Nuclear Chemistry. 31 (9). Institute of Physical Chemistry of the Academy of Sciences of the USSR: 2733–2745. doi:10.1016/0022-1902(69)80187-9.
  2. ^ Robert J. Lemire (2001). Lemire, Robert (ed.). Chemical Thermodynamics of Neptunium and Plutonium. Elsevier Science. p. 116. ISBN 9780444503794.