Thermodynamics Research Center / ThermoML | Journal of Chemical and Engineering Data

ABSTRACT

The mean activity coefficient of NaCl in NaCl-SrCl2-H2O was measured at 308K by electromotive force method. The total ion strength range of the mixed solution was 0.0100-1.0000mol*kg-1 and ion intensity fraction of SrCl2Yb =(0.8, 0.6, 0.4, 0.2, 0) for the different ion strength of SrCl2. An liquid-free electrochemical cell (Na-ISE | NaCl(m1)SrCl2(m2)| Cl-ISE) was used to determine the electromotive force of NaCl single salt and mixed solution. According to experimental data, a series of activity coefficient diagrams are drawn. The experimental results show that the measured activity coefficients are accurate and reliable, and the average activity coefficient of NaCl decreases with the increase of the ion strength of SrCl2. Using the measured average activity coefficient of NaCl, the parameters of the mixed ion action of the Pitzer equation + *2 + and + 2 + are fitted. Furthermore,the Pitzer equation is used to calculate the average activity coefficient SrCl2 the water activity aw osmotic coefficients Gibbs free energy GE of the mixed system.