Ultrasonic velocities and isentropic compressibilities of electrolytes in 2-methoxyethanol from 15 to 35 degrees C

The ultrasonic velocities of lithium tetrafluoroborate (LiBF4), sodium tetr afluoroborate (NaBF4), tetraphenylphosphonium chloride (Ph4PCl), tetrapheny lphosphonium bromide (Ph4PBr), and tetraphenylarsonium chloride (Ph4AsCl) i n 2-methoxyethanol (ME) have been measured at 15, 25, and 35 degreesC. Appa rent molar isentropic compressibilities kappa (phi) of these electrolytes w ere derived from these data supplemented with their densities. Infinite dil ution partial molar compressibilities kappa (o)(phi) were obtained by extra polation from the plot of kappa (phi) vs. the square root of the molarity. The kappa (o)(phi) values of the electrolytes were split into approximate l imiting ionic compressibilities kappa (o)(phi +/-) on the basis of the assu mption that kappa (o)(phi) (BF4-) = 0. The results have been interpreted in terms of specific constitutional and structural factors of the solvent mol ecules and of solute ions.