Praseodymium Tungstate

Praseodymium Tungstate is obtained as a greenish-yellow gelatinous precipitate when the chloride is added to a solution of sodium tungstate; unlike the corresponding neodymium salt, its solubility in water increases with rise in temperature.

By boiling praseodymium hydroxide with aqueous ammonium paratungstate and evaporating to dryness, the complex salt, 2(NH₄)₂O.Pr₂O₃.16WO₃.16H₂O, is obtained as a green transparent gum. The corresponding barium and silver salts, having composition 4BaO.Pr₂O₃.16WO₃.7H₂O, 6BaO.Pr₂O₃.16WO₃.9H₂O, and 4Ag₂O. Pr₂O₃.16WO₃.8H₂O, have also been prepared.