Barium Fluosilicate, BaSiF₆

Barium Fluosilicate, BaSiF₆, is obtained by precipitation of a barium salt with hydrofluosilicic acid. It forms microscopic needles of density 4.28 at 21° C. It is not very soluble in water, one part dissolving in 3731 parts of water at 17.5° C., and in 1175 parts at 100° C. It is practically insoluble in alcohol, but dissolves with decomposition in dilute hydrochloric acid. On calcination, silicon fluoride is given off and barium fluoride remains.