Potassium paramolybdate

Potassium paramolybdate crystallises in prisms isomorphous with the corresponding ammonium salt (p. 138). Tlie fused anhy-drous salt is but slightly soluble in water. 

Cadmium Molybdates.— The normal salt CdMoO is obtained as a heaY-y white precipitate when a soluble cadmium salt is added to a solution of an alkali molybdate or paramolybdate. The precipitate is readily soluble in mineral acids, ammonium hydroxide, or aqueous potassium cyanide. By fusing together sodium molybdate (2 parts), cadmium chloride (7 parts), and sodium chloride (6 parts), the salt may be obtained as lustrous yellow crystals. ... 

Dissolve 34 g of powdered ammonium paramolybdate in 1000 ml of distilled water. Add 400 ml of analytical reagent quality concentrated sulphuric acid a little at a time with mixing. Cool. Add 0.25 g of potassium antimonyl tartrate after first dissolving the salt in about 20-30 ml of water. Finally, add a fiurther 2500 ml of water, mix the whole, and store in plastic. The solution is stable for many months in a well-stoppered bottle. 

The multi-component LDHs (precursors) were prepared by reacting magnesium and aluminum nitrate solutions with a potassium hydroxide + potassium carbonate solution followed by anionic exchange to incorporate of decavanadate-, paramolybdate-, oxoniobate- and oxotungstate-iones into LDHs accordingly to experimental procedures... 

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