Rubidium uranate

Rubidium Uranate, RbjUO, is obtained by fusion of rubidium cliloride with the green oxide of uranium. ... 

TJranyl nitrate forms double salts of the type E U02(N03)3, where R =K, NH4, Rb, Cs, or Tl. They may be prepared by crystallising a solution of the mixed nitrates in concentrated nitric acid or by crystallisation from a solution of the alkali uranate in excess of nitric acid. The crystals are all anhydrous, and in the case of the potassium salt are orthorhombic, whilst the rubidium and caesium salts are rhombo-hedral and isomorphous with each other. The ammonium salt yields both orthorhombic and rhombohedral crystals. All exhibit a yellowish-green fluorescence they are liygroscopic and readily decomposed by water into their components. The thallium salt is particularly unstable, being decomposed in moist air. On the other hand, the rubidium salt dissolves in water at 80° C. without decomposition. The corresponding salts of sodium, lithium, or of divalent metals have not been prepared. 

The same type of reactions occur inside the fuel elements of nuclear reactors, where the two alkali metals rubidium and cesium are present as fission products. For instance, in the cesium-uranium-oxygen system two compounds, namely CS2UO4. or Cs2U40,2, are existent. In contact with liquid cesium, only CS2UO4 is stable. In case of absence of cesium metal in the reaction mixture, the other uranate can also be formed... 

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