298.15K下Li_2B_4O_7-H_2O体系水蒸汽分压及渗透系数的等压测定和离子相互作用模型  

Isopiestic Determination of Vapor Pressures and Osmotic Coefficients and the Ion-interaction Model for Li_2B_4O_7-H_2O System at 298.15 K

作　　者：张爱云[1] 姚燕[1] 宋彭生[1] 

机构地区：[1]中国科学院青海盐湖研究所

出　　处：《高等学校化学学报》2004年第10期1934-1936,共3页Chemical Journal of Chinese Universities

基　　金：国家自然科学基金 (批准号 :2 98710 3 4)资助

摘　　要：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.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.

关 键 词：等压法 渗透系数 饱和蒸汽压 离子相互作用模型 含硼体系 水溶液 

分 类 号：O645[理学—物理化学] O613.81[理学—化学]