Ultrasonic studies in the ternary mixtures: Water + Iso-propanol +Pyridine at 303.15 K

Ultrasonic velocities and densities have been measured for the ternary system of water, iso-propanol and pyridine as a function of composition at 303.15 K and at atmospheric pressure. From these data, experimental compressibilities and excess compressibilities have been calculated. The excess compressibilities are negative throughout the concentration range of pyridine. These results have been analyzed on the basis of the variations in ultrasonic velocities, compressibilities and excess compressibilities. The presence of weekly bonded alcohol+pyridine structures are noticed in the mixtures of pyridine and iso-propanol. The results are discussed in the light of the formation and breakdown of clathrate-like structures and complexes in binary and ternary mixtures.