吉布斯吸附等温式的应用—电解质溶液活度测定新方法  

Application of Gibbs adsorption isotherm—A new method to measure activity of electrolyte solutions

作　　者：陈辉煌[1] 陈启元[1] 刘常青[1] 张平民[1] 胡久刚[1] 

机构地区：[1]中南大学化学化工学院有色金属资源化学教育部重点实验室,长沙410083

出　　处：《中国有色金属学报》2014年第7期1878-1882,共5页The Chinese Journal of Nonferrous Metals

基　　金：国家自然科学基金资助项目(51134007);国家重点基础研究发展计划资助项目(2014CB643401)

摘　　要：采用最大气泡压力法测定298．15K，常压及不同离子强度（0．57～12．81mol／kg）条件下氯化钻水溶液体系的表面张力，建立表面张力与浓度关系的经验公式。应用Gibbs吸附等温式推导出表面张力与活度的关系式，提出一种计算溶液活度因子的新模型，并利用实验数据回归得出了新模型参数。与文献中的数据相比，新模型计算数据的标准偏差为O．0632，与Kim归纳出的Pitzer模型参数计算数据的标准偏差相近。结果表明：采用电解质溶液活度测定新方法和计算模型可得到的氯化钴水溶液活度因子的精度较高，这使得通过测定电解质溶液表面张力计算其活度因子（或活度）成为可能。The surface tension of cobalt chloride aqueous solution was determined using the maximum bubble pressure method at 298.15 K and constant pressure with ionic strength ranging from 0.57 to 12.81 mol/kg, and the empirical formula of surface tension as a function of concentration was constructed. The relationship between surface tension and activity was derived by applying Gibbs adsorption isotherm, and a new model to calculate activity coefficient was proposed and regressed based on experimental values. Compared with literature values, the standard deviation of results calculated from the new model is 0.0632, which is close to that of Pitzer equation parameters generalized by Kim. Thus, it can be concluded that the new model provides a new approach to calculate activity coefficients （or activity） of electrolyte solutions with a relatively high precision by measuring the surface tension.

关 键 词：电解质溶液 活度因子 表面张力 最大气泡压力法 氯化钴 吉布斯吸附等温式 

分 类 号：O645.17[理学—物理化学]