The ultrasonic velocity, density and viscosity for binary liquid mixtures of the n-alcohols namely 1-pentanol, 1- hexanol and 1-heptanol in toluene, carbon tetra chloride, benzene and dioxane at 301K have been measured. From these measured parameters adiabatic compressibility, free length, free volume and their excess values have been measured. The results have been analyzed and interpreted in terms of molecular interactions such as dipole-dipole interaction through hydrogen bonding between solvents and 1-alkanols have been observed. Further the experimental ultrasonic velocities of all these binary systems are compared with theoretical ultrasonic velocity.