| Stannous Fluoride, SnF2, is formed when the metal or the monoxide is dissolved in hydrofluoric acid, and is obtained on evaporation of the solution in white, monoclinic prisms, stable in air and completely soluble in water. Stannous fluoride appears to combine with hydrofluoric acid and alkali fluorides forming complex acids and salts of the types HSnF3 and H2SnF4. |