Sodium Thiomolybdates

Two are known: the normal salt, Na₂MoS₄, prepared as dark reddish crystals by the action of hydrogen sulphide upon a solution of sodium molybdate, and the acid salt, Na₂Mo₂S₇, obtained as a dark grey mass by treatment of the normal salt with a deficiency of acid. Oxythiomolybdates are obtained by the action of sodium hydrosulphide upon sodium tri- and para-molybdates.