Strontium Fluosilicate, SrSiF₆

Strontium Fluosilicate, SrSiF₆, is prepared by evaporating to dryness a solution of strontium carbonate in excess of hydrofluosilicic acid, treating with water, filtering to remove silica, and allowing to crystallise. It forms monoclinic crystals of composition SrSiF₆.2H₂O, and density 2.99 at 17.5° C., which, on being heated, give first water and then silicon fluoride. It is decomposed by water and by all acids except dilute hydrofluosilicic acid.

One part of the salt dissolves in 31 parts of water at 15° C., and in 1529 parts of 50 per cent, alcohol.