ДОСЛІДЖЕННЯ ВЗАЄМОДІЇ Hg(II) З КАЛІЙ ТРИЙОДИДОМ В УМОВАХ ЕЛЕКТРОТИТРИМЕТРІЇ

The processes of interaction of mercury(II) with potassium triiodide have been studied in various media by potentiometric and biamperometric methods. It was concluded that acetate buffer solutions with pH 4–6 are the optimal background electrolyte. It has been established that the formation of the final products i.e. HgI2 and Hg(IO3)2 proceeds with the formation of intermediate mixed complexes with acetate ions. It was shown that the platinum electrode is amalgamated as a result of continuous work with solutions of mercury. In connection with this, the anomalous curves of biamperometric titration of mercury (II) with KI3 solution were obtained. In potentiometric titration, a decisive contribution to the magnitude of the potential is made by mixed oxidation-reduction potentials. The obtained results were used for the development of the procedure for the determination of mercury (II) by potassium triiodide with fixation of the equivalence point by electrochemical methods.