Preparation of tetravalent praseodymium in potassium phosphotungstate aqueous solutions

The possibility has been studied of oxidizing Prsup((3)) to Prsup((4)) when Prsup((3)) is added to an aqueous weakly-acid solution containing K10[P2W17O61H2O] x H2O. A sharp change in the solution colouring has been observed as a result of Prsup((3)) oxidation to Prsup((4)). The absorption spectra of solution of Prsup((4)) have been recorded and the values of the molar extinction coefficients have been determined. On storage of the solution, Prsup((4))reduces to Prsup((3)) with a half-reduction period of 0.2-0.5 hour