Thermodynamics Research Center / ThermoML | Journal of Chemical and Engineering Data

ABSTRACT

The density of the binary system composed of 1-propanol and toluene has been measured under pressure using a vibrating tube densimeter. The measurements have been performed for four different compositions as well as the pure compounds at four temperatures in the range 303.15 K to 333.15 K and seven isobars up to 30 MPa. The uncertainty of the reported densities is less than 0.05 %. The measured data has been used to study the influence of temperature, pressure and composition on the isothermal compressibility and the isobaric thermal expansivity as well as the excess molar volume, which shows a complex sigmoid behavior involving both positive and negative values. This complex behavior has been interpreted as the result of changes in the free-volume due to volume expansion and compressibility as a result of breaking of hydrogen bonds of the self-associating alcohol molecules, but also due to the electron donor-acceptor type formation of hydrogen bonding between the hydroxyl group of 1-propanol and the electrons of toluene, since aromatic hydrocarbons can act as electron donors.