Lithium thiosulphate, Li₂S₂O₃

The trihydrate, Li₂S₂O₃,3H₂O, is prepared by the interaction of barium thiosulphate and lithium sulphate in aqueous solution. Heating eliminates the water of crystallization, and then decomposes the anhydrous substance into sulphur, sulphate, and sulphide. The salt is very deliquescent.