文献类型：期刊文献

英文题名：Activity coefficients of CaCl2 in (serine or proline plus water) mixtures at T=298.15 K

作者：Ma, Jingjing[1];Zhang, Xinkuan[1,2];Zhuo, Kelei[1];Liu, Hongxun[1];Wang, Jianji[1]

第一作者：Ma, Jingjing

通讯作者：Zhuo, KL[1]

机构：[1]Henan Normal Univ, Sch Chem & Environm Sci, Xinxiang 453007, Henan, Peoples R China;[2]Xinxiang Univ, Sch Chem & Chem Engn, Xinxiang 453003, Henan, Peoples R China

第一机构：Henan Normal Univ, Sch Chem & Environm Sci, Xinxiang 453007, Henan, Peoples R China

通讯机构：[1]corresponding author), Henan Normal Univ, Sch Chem & Environm Sci, Xinxiang 453007, Henan, Peoples R China.

年份：2010

卷号：42

期号：5

起止页码：689-694

外文期刊名：JOURNAL OF CHEMICAL THERMODYNAMICS

收录：;WOS:【SCI-EXPANDED(收录号:WOS:000276579700017)】；

基金：Financial supports from the Innovation Foundation of Colleges and Universities of Henan Province and the National Natural Science Foundation of China (No. 20673033) are gratefully acknowledged.

语种：英文

外文关键词：Activity coefficient; Gibbs free energy; Pair interaction parameter; CaCl2; Serine; Proline

摘要：Activity coefficients for the (CaCl2 + amino acid + water) system were determined at a temperature of 298.15 K using ion-selective electrodes. The range of molalities of CaCl2 is (0.01 to 0.20) mol.kg(-1), and that of amino acids is (0.10 to 0.40) mol.kg(-1). The activity coefficients obtained from the Debye-Huckel extended equation and the Pitzer equation are in good agreement with each other. Results show that the interactions between CaCl2 and amino acid are controlled mainly by the electrostatic interactions (attraction). Gibbs free energy interaction parameters (g(EA)) and salting constants (k(S)) are positive, indicating that these amino acids are salted out by CaCl2. These results are discussed based on group additivity model. (C) 2010 Published by Elsevier Ltd.