Thermogravimetric Analysis (TGA) of the Sulphides of  Selenium (IV), Tellurium (IV) and Vanadium (V) obtained  with Potassium Thiocarbonate (PTC)

Unlike the conventional use of H₂S as precipitant, potassium thiocarbonate (PTC) yields sulphides of selenium (IV), tellurium (IV) and vanadium (V) confirming to the stiochiometric composition of SeS₂, TeS₂ and V₂S₅, respectively. The procedure of precipitation in each case is based on the acidification of the thio­carbonato-complex, initially obtained with excess PTC. Thermogravimetric analysis (TGA) not only con­firms the purity of the precipitated products but determines correct temperature ranges for the precipitates to attain constant weight affording gravimetric estimation of Se, Te and V.