Silver thiosulphate, Ag₂S₂O₃

Precipitation of a solution of sodium thiosulphate with Silver nitrate yields the Silver thiosulphate, Ag₂S₂O₃, as a white precipitate of sweetish taste. It dissolves in solutions of other thiosulphates, forming double salts. As examples of such salts isolated from solutions of silver chloride in thiosulphates may be cited Ag₂S₂O₃,2Na₂S₂O₃,2H₂O, leaflets of silk-like lustre, readily soluble in water; Ag₂S₂O₃,Na₂S₂O₃,H₂O, small, hard, columnar crystals of slight solubility and sweet taste; Ag₂S₂O₃,3K₂S₂O₃,2H₂O; Ag₂S₂O₃,(NH₄)₂S₂O₃, columnar crystals of intensely sweet taste. A double salt of the formula 3Ag₂S₂O₃,5K₂S₂O₃ crystallizes in prismatic needles from a solution of Silver nitrate and sodium thiosulphate on addition of potassium carbonate. Additive compounds of this type, and others with ammonia, have been exhaustively studied by Jonsson.