Density and excess molar volumes of binary mixtures of sulfolane with methanol, n-propanol, n-butanol, and n-pentanol at 298.15–323.15 K and atmospheric pressure

Abstract

Densities, ρ and excess molar volumes, V ^E of the binary mixtures of sulfolane, +methanol, +n-propanol, +n-butanol, and +n-pentanol were measured at temperatures 298.15, 303.15, 308.15, 313.15, and 318.15 K, respectively, covering the whole composition range except methanol at 303.15–323.15 K. The V ^E for the systems were found to be negative and large in magnitude. The values of V ^E of the sulfolane, +n-butanol and sulfolane, +n-pentanol mixtures are being positive at lower and higher mole fractions of the alkanols (x ₂). The magnitudes of the V ^E values of the mixtures are in the order sulfolane + methanol > sulfolane + n-propanol > sulfolane + n-butanol > sulfolane + n-pentanol. The observed values of V ^E for the mixtures have been explained in terms of (i) effects due to the differences in chain length of the alcohols, (ii) dipole–dipole interactions between the polar molecules, and (iii) geometric effect due to the differences in molar volume of the component molecules. These are more noticeable in the case of lower alcohols. All these properties have been expressed satisfactorily by appropriate polynomials.

Keywords:

• Excess molar volumes
• Sulfolane
• Methanol
• n-Propanol
• n-Butanol
• n-Pentanol