Magnesium Paramolybdate, 3MgO.7MoO₃.20H₂O

Magnesium Paramolybdate, 3MgO.7MoO₃.20H₂O, may be prepared by the action of nitric acid on magnesium molybdate in solution; upon evaporation, small transparent prisms are obtained.

The salt is readily soluble in water. It is stable at atmospheric temperature, and becomes anhydrous on heating.

From a solution containing ammonium paramolybdate (1 molecule) and magnesium nitrate (2 molecules) colourless crystals have been obtained, which may be formulated (NH₄)₃.Mg.H₅[H₂(MoO₄)₆].6H₂O.