1,3—丙二醇在水、乙醇溶液中的体积性质

Volumetric Properties of Mixture for 1,3—propanediol in Water and Ethanol

利用密度计测得常压下的混合液密度,计算1,3—丙二醇分别在水和乙醇溶液中328.15、338.15、348.15K温度下全浓度范围的表观摩尔体积和偏摩尔体积,本文用修正的Redlich—Meyer方程拟合混合液的表观摩尔体积与溶质浓度关系,最大标准偏差低于0.05 ml.mol-1,并与Redlich—Kister方程得到的偏摩尔体积比较.数据表明,溶质在溶剂中无限稀释偏摩尔体积和极限表观摩尔体积是一致的,1,3—丙二醇在乙醇里的无限稀释超额偏摩尔体积负偏差较水中更大,说明溶质—溶剂间的交叉缔合作用较溶剂内分子间作用大,且1,3—丙二醇与乙醇的分子间作用强于1,3—丙二醇与水分子间作用.

The apparent molar volumes, partial molar volumes of 1,3-proponediol in water and ethanol were determined from the experimental density data over the whole composition range at 328.15 338.15,348.15 K and atmospheric pressure with densimeter. The two binary data for apparent molar volume as a function of composition were fit to the modified Redlich - Meyer type equation with the most standard deviation less than 0.05 ml·mol^-1. and compared with The correlated value of partial molar volumes using Redlich- Kister polynomial. It was found that agreement is satisfactory between partial molar volumes at infinite dilution and limits apparent molar volumes, and The limits values of partial molar volumes of 1,3-propanediol in ethanol were more negative than in water. The results indicate that the molecular interactions of solute-solvent type is stronger than the like molecular of solvent and 1, 3-propanediol-solvent interactions in ethanol are stronger than those in water.