Sodium Orthoxymonothiovanadate, Na₃VSO₃,10H₂O

Sodium Orthoxymonothiovanadate, Na₃VSO₃.10H₂O, has been obtained in orange-yellow crystals by the action of sodium hydrosulphide on sodium pyrovanadate.

The action of hydrogen sulphide at high temperatures on sodium pyrovanadate gives rise to sodium pentathiopyrovanadate, Na₄V₂S₅O₂, which is a hygroscopic substance very similar in its colour and lustre to potassium permanganate.

Thiovanadates of the heavy metals have proved difficult to isolate; addition of solutions of salts of zinc, manganese, copper and silver to a solution of ammonium thiovanadate gives precipitates which consist of sulphides or thiovanadates of the metals, or mixtures of both. A black, crystalline lead salt of the probable composition Pb₂V₂S₂O₅, lead dithiopyrov anadate, has, however, been obtained.