The application of thiosalts in analysis : Estimations based on decomposition of thiosalts part B. estimation of molybdenum and tin

1. It has been shown that molybdenum can be precipitated quantitatively by adding excess of concentrated ammonium sulphide to a molybdate solution and then decomposing the thiosalt with excess of hydrochloric acid. 2. The weight of the precipitate corresponds to the formula MoS₃.2H₂O and the quantity of metal can be estimated by multiplying the weight of the precipitate by a constant factor. 3. The same method is also applicable to the gravimetric estimation of tin. The precipitate of stannic sulphide is easily filterable and its weight corresponds to the formula SnS₂.2H₂O. 4. The general method in its simple form has not been found to be applicable to vanadium, platinum and gold.