K^+/Cl^-,Br^-H_2O三元体系298K,313K,333K时的相平衡

Phase Diagram for the Ternary System of K+/Cl^-, Br^--H_2O at 298 K,313 K and 333 K

用等温溶解平衡法测定了三元体系K+/Cl-,Br--H2O298K、313K、333K时的相平衡数据,同时还测定了饱和溶液的密度、折光率等物化性质,依据湿渣法与X射线衍射相结合的方法对平衡固相组成进行了鉴定。该三元体系298K、313K、333K的溶解度等温图有1个固相区:K(Cl,Br),有1条单变量曲线,该体系属于固体溶液型。用Pitzer模型计算测得的三元体系298K、313K、333K溶解度,并用经验公式对平衡液相的密度、折光率进行了计算,计算值与实验值基本吻合。

Solubilities of the ternary system of K^＋/Cl^-,Br^-H2O were investigated at 298 K, 313 K, 333 K by isothermal method. Physicochemical properties of the saturated solutions, such as density and refractive index, were determined. The nature of the equilibrium solid phase was also verified by analyzed wet residue and X ray spectroscopy. Based on the solubility data, the phase diagram of the ternary system at 298 K, 313 K, 333 K was obtained, which comprises one univariant curve and one stationary phase in crystallization region of K（Cl,Br）. The ternary system is a solid solution. Pitzer model of mixed electrolyte solution was used to check the obtained solubilities, and the physicochemical properties of the system were discussed briefly. The empirical equations of density and refraetive index related to its composition were used to correlate the data. Differences between measured and calculated values are less than 1.58% for density and 0.22% for the refractive. The calculated values are in agreement with the experiment values on the whole.