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

ABSTRACT

Apparent molar heat capacities and apparent molar volumes were measured for all isomeric C3 to C5 alkanols in their dilute aqueous solutions at 298.15 K using a differential flow microcalorimeter in conjuntion with a vibrating-tube densimeter. Molar volumes and molar heat capacities of the pure alkanols (except for 2-methyl-2-propanol and 2,2-dimethyl-1-propanol, which are solid at 298.15 K) were determined using the same instrumentation. The concentration dependence of the apparent properties allowed the determination, through extrapolation, of the infinite dilution partial molar volumes and heat capacities of these alkanols in water. These values, combined with the respective pure liquid properties, produced the limiting partial molar excess quantities. The present measurements agree well with available literature values. The group contribution schemes of Cabani et al. (Cabani, S.; Gianni, P.; Mollica, V.; Lepori, L. Group Contribution to the Thermodynamic Properties of Non-Ionic Organic Solutes in Dilute Aqueous Solution. J. Solution Chem. 1981, 10, 563-595) and of Plyasunov and Shock (Plyasunov, A. V.; Shock, E. L. Thermodynamic Functions of Hydration of Hydrocarbons at 298.15 K and 0.1 MPa. Geochim. Cosmochim. Acta 2000, 64, 439-468) were used to predict the limiting partial molar properties. It was found that the predictions of both schemes are very good.