Excess volumes, isentropic compressions, and isobaric heat capacities for methanol mixed with other alkanols at 25°C

Abstract

Excess volumes, excess isentropic compressions and excess isobaric heat capacities for binary liquid mixtures of methanol with ethanol, 1-propanol and 1-butanol have been determined at 25° C. These thermodynamic functions are smaller than those for alkanol + water mixtures and are correlated with the difference in the alkyl chain length in two of the alkanol molecules. The behavior of the component molecules in solution is found to be similar to that in the pure liquid. The excess isentropic compressions of methanol + 1-butanol show an S-shaped concentration dependence with a positive lobe in the methanol rich range and a negative lobe in the methanol poor range, which resembles that of the excess Gibbs energy reported by Polak et al.