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, (V) over bar degrees(m,1) and (V) over bar degrees(m,2), at infinite dilution, and excess partial molar volumes, (V) over bar degrees(E)(m,1) and (V) over bar degrees(E)(m,2) at infinite dilution were calculated. The variation of these parameters with composition and temperature of the mixtures are disucussed in terms of molecular interactions in these mixtures. The partial molar expansivities, (E) over bar degrees(2) and (E) over bar degrees(2), at infinite dilution were also calculated. The V-m(E) values were found to be positive for all 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.