Study of molecular interaction in binary mixtures of 1,4-dioxane + 1-alkanols

Densities p and ultrasonic velocities u have been measured in binary mixtures of 1,4-dioxane with 1-hexanol, 1-octanol and 1-decanol as a function of composition at 308.15K. Isentropic compressibility K s , intermolecular free length L f , molar sound speed R m , relative association R A , acoustic impedence Z, molecular association M A , excess isentropic compressibility K s E , excess volume V E , excess ultrasonic speed u E , and excess acoustic impedance Z E , have been calculated from these measurements. The values of K s E and V E were found to be positive, and those of u E and Z E negative, for all the three systems investigated, over the entire composition range. This indicates weak interaction between the component molecules, decreasing in the order: 1-hexanol > 1-octanol > 1-decanol. Theoretical values of ultrasonic speed in all these binary mixtures have been evaluated using different theories and empirical relations, and the relative merits of these theories and relations examined.