Densities and Volumetric Properties of Binary Mixtures of Formamide with 1-Butanol, 2-Butanol, 1,3-Butanediol and 1,4-Butanediol at Temperatures between 293.15 and 318.15 K

摘要

The densities of binary mixtures of formamide (FA) with 1-butanol, 2-butanol, 1,3-butanediol, and 1,4-butanediol, including those of the pure liquids, over the entire composition range were measured at temperatures (293.15, 298.15, 303.15, 308.15, 313.15 and 318.15) K and atmospheric pressure. From the experimental data, the excess molar volume, V m E, partial molar volumes, $smash{overline V _{m,1}^circ }$ and $smash{overline V _{m,2}^circ }$ , at infinite dilution, and excess partial molar volumes, $smash{overline V _{m,1}^{circ {rm E}}}$ and $smash{overline V _{m,2}^{circ {rm E}}}$ , at infinite dilution were calculated. The variation of these parameters with composition and temperature of the mixtures are discussed in terms of molecular interactions in these mixtures. The partial molar expansivities, $smash{overline E _1^circ}$ and $smash{overline E _2^circ}$ , at infinite dilution and excess partial molar expansivities, $smash{overline E _1^{circ {rm E}}}$ and $smash{overline E _2^{circ {rm E}}}$ , at infinite dilution were also calculated. The V m E values were found to be positive for all the mixtures at each temperature studied, except for FA + 1-butanol which exhibits a sigmoid trend wherein V m E values change sign from positive to negative as the concentration of FA in the mixture is increased. The V m E values for these mixtures follow the order: 1-butanol < 2-butanol < 1,3-butanediol < 1,4-butanediol. It is observed that the V m E values depend upon the number and position of hydroxyl groups in these alkanol molecules.