Calcium Metavanadate, Ca(VO₃)₂

Calcium Metavanadate, Ca(VO₃)₂. - A tetrahydrate, Ca(VO₃)₂. 4H₂O, separates as yellowish-white crystals on evaporating a mixture of an alkali vanadate and calcium chloride solutions. It loses all its water at 180° C. On treating a mixture of ammonium metavanadate and calcium chloride solutions with alcohol, bright yellow needles of the trihydrate, Ca(VO₃)₂.3H₂O, are obtained.

A double acid calcium potassium vanadate is known, CaO.4K₂O.10V₂O₅.22H₂O.

A number of acid salts have been obtained by precipitation from acid solutions; among them are, CaO.2V₂O₅.9H₂O, CaO.2V₂O₅.6H₂O, 3CaO.4V₂O₅.15H₂O, 3CaO.8V₂O₅.26H₂O, and CaO. 3V₂O₅.12H₂O. They all form red crystals.