用等压法研究了298.15 K下L iC l-L i2B4O7-H2O体系在不同L iB4O7质量摩尔浓度时的等压平衡浓度,水活度;计算了L iC l和L i2B4O7混合盐溶液的渗透系数等热力学性质.用298.15 K下的实验数据对P itzer离子相互作用模型进行了参数化研究,拟合求取了298.15 K下P itzer离子相互作用参数,用获得的参数计算了L iC l和L i2B4O7在L iC l-L i2B4O7-H2O体系中的活度系数.P itzer模型计算的渗透系数值与实验结果一致.
Isopiestic molalities, vapor pressures and osmotic coefficients of aqueous Li 2B 4O 7 solutions from 0.027 5 to 2.939 7 mol/kg were determined at 298.15 K by using an improved apparatus. The rule of the changes in vapor pressure over aqueous Li 2B 4O 7 solutions was revealed, which indicated that the bond of borate anions with water are better than that of NaCl. The different formation reaction equilibria for the species containing boron of boric acid and borate anions B(OH) - 4, B 3O 3(OH) - 4 and B 4O 5(OH) 2- 4 in Li 2B 4O 7(aq) solutions were taken into account. The stoichiometric equilibrium constants for the formation reactions of the boron species and the ion-interaction parameters were estimated simultaneously by using Pitzer equations of osmotic coefficient with minor modifications. Sixteen parameters were obtained with a standard deviation 0.005 5 for the ion-interaction model.
