Transference numbers in concentrated sodiumchloride solutions

The transference numbers of sodium and chloride ions in concentrated NaClwater solutions have been measured at 25°C, using the Hittorf method. An improvement to determine the concentration has been obtained by weighing the anhydrous salt content of the different portions. The ionic conductivities calculated by data of transference numbers and conductivities of the salt have been compared to the analogous quantities of NaClO4-water system. The analysis of the data seems to prove the existence of a different concentration region where the structural transition of the solutions greatly influences the ionic mobility