Heteropoly Salts

Summary The trialkali and dialkali hydrogen phosphomolybdates of caesium and rubidium have been isolated. Methods are given for their preparation and also suggested methods for the preparation of corresponding salts of potassium, ammonium, and monovalent thallium. The tetra alkali, trialkali hydrogen, and dialkali dihydrogen silicotungstates of caesium, rubidium, and potassium have also been shown to exist and methods are given for their preparation. The relative solubilities of the alkali phosphomolybdates and silicotungstates in water and their stabilities in acid solution have been ascertained.