Ultrasonic study of molecular association in liquid mixtures

Ultrasonic study of 1:1 mixture of ethyl acetate/butyl acetate and phenol/n-butyl alcohol in carbon tetrachloride (low concentration region) have been carried out at a frequency of 1 MHz and temperature of 30 degrees C. Using the measured ultrasonic velocity and density, adiabatic compressibility, inter-molecular free length, molar sound velocity and molar compressibility have been calculated. The ultrasonic velocity shows a maxima and adiabatic compressibility a corresponding minima as a function of concentration for the two mixtures containing phenol and the third one containing ethyl acetate and n-butyl alcohol. The mixture containing butyl acetate and n-butyl alcohol exhibits an increase of velocity with increasing concentration. The results indicate a possible complex formation between the unlike molecules through hydrogen bonding.