Abstract:

The new method of Pseudo-Static Ebulliometer for determining osmotic coefficients of nonaqueous electrolyte solutions was developed at constant temperature. Aset of experimental apparatus was constructed. This apparatus was calibrited with NaCl, NaBr in methanol solvent. The results are consistant with the literature values, showing that the apparatus is reliable and the accuracy is high also. The osmotic coefficients of solutions of Nal, Me4NCl, Bu4NBr in methanol solvent were measured at 298.15K. The results are fitted by Pitzer equation. The activity coefficients of salts in methanol are calculated using Pitzer’s interaction parameters obtained. The method is rapid, convenient and accurate, compared with the traditional static and isopiestic methods. It gives a powerful tool for measurement of the osmotic coefficients of nonaqueous electrolyte solutions.

Key words: Nonaqueous electrolyte solution, Osmotic coefficients, Pseudo-static ebulliometer