应用等温流动微量热法测定了298.15K时木糖醇在纯水和碱金属卤化物水溶液中的稀释焓,根据Mc Millan Mayer理论计算了木糖醇在溶液中的二到四阶焓相互作用系数.结果表明,木糖醇在碱金属卤盐溶液中的焓对相互作用系数h2均为正值,h2值随着碱金属阳离子或卤素阴离子半径的增大皆依次增大.根据木糖醇参与的溶质-溶质,溶质-溶剂等弱相互作用,对该种多元醇在碱金属卤盐水溶液中的焓相互作用系数的变化进行了解释.
The enthalpies of dilution of xylitol in water and aqueous alkali halide solutions have been determined by using flow-mix-isothermal microcalorimetry at 298.15 K. The enthalpic interaction coefficients in the range of alkali salt solutions have been calculated according to the McMillan-Mayer theory. Enthalpic pairwise interaction coefficients (h2) of xylitol are positive in aqueous alkali-halogen salt solution. The important tendency is that value of h2 becomes more positive with the increase of the radius of alkali salt cation or haloid anion. The results were discussed in terms of the different alkali salt ions, interactions of solute with solute and solute with solvent.