Densities and Volumetric Properties of Binary Mixtures of Aniline with 1-Propanol, 2-Propanol, 2-Methyl-1-Propanol, and 2-Methyl-2-Propanol at Temperatures from 293.15 to 318.15 K

The densities of binary mixtures of aniline with 1-propanol, 2-propanol, 2-methyl-1-propanol, and 2-methyl-2-propanol were measured over the entire composition range, along with the pure components, at temperatures of 293.15, 298.15, 303.15, 308.15, 313.15, and 318.15 K and atmospheric pressure. Using the experimental data, the excess molar volumes, $V_{\rm m}^{\rm E}$ , and the temperature coefficients of the excess molar volume, $\partial V_{\rm m}^{\rm E}/\partial T$ for the binary mixtures were calculated. The variations of these parameters with composition and temperature of the mixtures have been discussed in terms of molecular interactions in these mixtures. The $V_{\rm m}^{\rm E}$ values were found negative for all the mixtures at each temperature studied, indicating the presence of specific interactions between aniline and alkanol molecules. The extent of negative deviations in $V_{\rm m}^{\rm E}$ values follows the order: 1-propanol < 2-propanol < 2-methyl-1-propanol < 2-methyl-2-propanol. It is observed that the $V_{\rm m}^{\rm E}$ values depend upon the positions of hydroxyl and methyl groups in these alkanol molecules.