Germanous Fluoride, GeF₂

Germanous Fluoride, GeF₂, is formed as a dark-coloured mass, mixed with metallic germanium, when potassium germanifluoride, K₂GeF₆, is heated in a current of hydrogen. The presence of the lower fluoride is shown by the formation of the brown monosulphide, GeS, when hydrogen sulphide is passed through the aqueous extract of the product.