Excess Enthalpy, Density, and Speed of Sound for the Mixtures β-Pinene + 2-Methyl-1-propanol or 2-Methyl-2-propanol at Several Temperatures

Abstract

Excess enthalpies, densities, and speeds of sound are reported for the binary mixtures β-pinene + 2-methyl-1-propanol at the temperatures (283.15, 298.15, 303.15, 313.15, and 323.15) K and β-pinene + 2-methyl-2-propanol at the temperatures (303.15, 313.15, and 323.15) K. Excess molar volumes have been calculated from the densities and speed of sound deviations, isentropic compressibilities, and excess isentropic compressibilities from speeds of sound. The excess properties and deviations of properties have been fitted to Pade approximants. Excess molar enthalpies and excess molar volumes are positive for both mixtures, whereas speed of sound deviations show both positive and negative values. Also, positive and negative values of excess isentropic compressibility are observed for the mixture β-pinene + 2-methy-1-propanol, but the mixture β-pinene + 2-methyl-2-propanol exhibits positive values only. The excess properties are compared with those of the mixtures of β-pinene with 1-butanol and 2-butanol.