Reduction of Germanium IV Oxide

The reduced solution is cooled in ice and neutralized with concentrated aqueous ammonia (50 to 60 ml.), until a 

0 + GeS + H3PO2 -1- 2HC1 GeCl -h H3PO3 -H 2H2S GeCl2 -I- H2S GeS -b 2HC1 

Five grams of germanium (IV) sulfide is suspended in 200 ml. of 6 N hydrochloric acid in a 500-ml. Eiienmeyer flask and treated with 50 ml. (excess) of a 50 per cent solution of hypophosphorous acid. The mixture is heated on a steam bath and stirred occasionally with a glass rod to disintegrate the lumps of unattacked sulfide. Hydrogen sulfide escapes slowly, and the sulfide disappears, leaving 

With lower acidity, the reduction requires a much longer time, and the germanium(IV) sulfide becomes coated with an orange layer of the (Il)sulfide, which does not dissolve in the dilute acid solution. 

Unlike germanium(IV) sulfide, which may be precipitated by means of hydrogen sulfide only from solutions that are more acid than 6 N, germanium(II) sulfide may be obtained only from weakly acid or alkaline solutions and redissolves if the acidity is increased. When dry, ger-manium(II) sulfide is stable in air. 

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