Acoustic and volumetric effects of self-association of 2-methyl-1-propanol in binary liquid mixtures at 293.15 K

Speeds of ultrasound and densities were measured in binary solutions of 2-methyl-1-propanol in hexane and in cyclohexane at 293.15 K in the whole concentration range. The results of the measurements in connection with literature data were used to calculate isothermal compressibility coefficients and isochoric molar heat capacities for the pure components. They were also used for finding out molar volumes, adiabatic compressibilities, free volumes and free intermolecular lengths for the mixtures under test. The composition dependences of excess molar volume, adiabatic compressibility and excess free volume were compared and discussed in terms of free intermolecular length, space-filling ability and other factors affecting the self-association of 2-methyl-1-propanol and entropy effects connected with structural changes of non-polar solvents accompanied solvation processes.