Acoustic and Thermodynamic Properties of Binary Liquid Mixtures of Benzaldehyde in Hexane and Cyclohexane

Densities and ultrasonic speeds of binary mixtures of benzaldehyde with n-hexane and cyclohexane at 30 °C were measured over the entire composition range. From these experimental data, the adiabatic compressibility (KS), intermolecular free length (Lf), acoustic impedance (Z), relative association (Ra) and relaxation strength (r) were calculated. Also, the excess adiabatic compressibility (KSE), intermolecular free length (LfE), acoustic impedance (ZE), and ultrasonic velocity (UE) were calculated. The observed variation of these parameters helps in understanding the nature of interactions in these mixtures. Further, theoretical values of the ultrasonic speed were evaluated using theories and empirical relations. The relative merits of these theories and relations were discussed.