298.15和308.15 K时1,2-丙二醇+MCl (M=Na,K, Rb,Cs)+H2O三元体系的溶解度、密度和折光率

系统研究了1,2-丙二醇+MCl (M=Na, K, Rb, Cs)+H₂O三元体系在298.15 和308.15 K时的等温相平衡. 采用硝酸汞滴定法测定了体系中无机盐的含量, 采用安东帕RXA170 折光率仪及DMA4500 密度计测定了所有体系的折光率和密度数值. 报道了1,2-丙二醇质量分数从0增加到0.9过程中饱和及不饱和三元溶液体系的等温溶解度、密度和折光率数据. 实验结果发现, 随着1,2-丙二醇的不断加入, 饱和溶液的溶解度和密度均呈现出减小的趋势, 而折光率的变化则呈现出相反的趋势. 采用经验方程关联了不同醇水比条件下不饱和溶液的密度和折光率实验数据, 获得了较为理想的拟合结果. 本研究的开展充实了碱金属盐在混合溶剂中的热力学数据, 为相关溶液化学研究奠定了基础.

Solubility, Density and Refractive Index for the Ternary Systems of 1,2-Propanediol, MCl (M=Na, K, Rb, Cs) and H2O at 298.15 and 308.15 K

In this paper, the liquid-solid equilibrium for the ternary systems composed of 1,2-propanediol, MCl (M=Na, K, Rb, Cs), and H₂O were studied at 298.15 and 308.15 K, with the mass fraction of 1,2- propanediol ranging from 0 to 0.9. The solubilities, densities, and refractive indices of the saturated systems, and the densities and refractive indices of the unsaturated solutions are reported herein. The solubilities were determined via a titration method using mercury nitrate as the titrant. Refractive index and density data were measured using an Anton Paar RXA170 refractometer and Anton Paar DMA4500 densimeter, respectively. The experimental values of the solubilities and densities of the saturated solutions decreased with increasing 1,2-propanediol concentration, whereas different trends of increase were observed for the refractive indices. The experimental density and refractive index data for the unsaturated solutions increased with increasing 1,2-propanediol to water ratios. Empirical equations have been provided for these properties as a function of concentration. On the basis of the standard deviations, we concluded that the empirical equations could be satisfactorily used to correlate the solubility, density, and refractive index data of the investigated systems. These values will enrich the thermodynamics data for alkali metals in mixed solvents, and lay a foundation for any subsequent work.