(中南大學 化學化工學院 有色金屬資源化學教育部重點實驗室，長沙 410083)
摘 要: 采用最大氣泡壓力法測定298.15 K，常壓及不同離子強度(0.57~12.81 mol/kg)條件下氯化鈷水溶液體系的表面張力，建立表面張力與濃度關系的經驗公式。應用Gibbs吸附等溫式推導出表面張力與活度的關系式，提出一種計算溶液活度因子的新模型，并利用實驗數據回歸得出了新模型參數。與文獻中的數據相比，新模型計算數據的標準偏差為0.0632，與Kim歸納出的Pitzer模型參數計算數據的標準偏差相近。結果表明：采用電解質溶液活度測定新方法和計算模型可得到的氯化鈷水溶液活度因子的精度較高，這使得通過測定電解質溶液表面張力計算其活度因子(或活度)成為可能。
關鍵字: 電解質溶液；活度因子；表面張力；最大氣泡壓力法；氯化鈷；吉布斯吸附等溫式
（Key Laboratory of Resource Chemistry of Nonferrous Metals, Ministry of Education,
School of Chemistry and Chemical Engineering, Central South University, Changsha 410083, China）
Abstract: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.
Key words: electrolyte solutions; activity coefficient; surface tension; maximum bubble pressure method; cobalt chloride; Gibbs adsorption isotherm
