Semi-ideal Solution Theory. 2. Extension to Conductivity of Mixed Electrolyte Solutions

Abstract

Conductivities were measured for the ternary systems NaCl-LaCl(3)-H(2)O and KCl-CdCl(2)-H(2)O and their binary subsystems NaCl-H(2)O, KCl-H(2)O, CdCl(2)-H(2)O, and LaCl(3)-H(2)O at 298.15 K. The semi-ideal solution theory for thermodynamic properties of aqueous solutions of electrolyte mixtures was used together with the Eyring absolute rate theory to study conductivity of mixed electrolyte solutions. A novel simple equation for prediction of the conductivity of mixed electrolyte solutions in terms of the data of their binary solutions was established. The measured conductivities and those reported in literature were used to test the newly established equation and the generalized Young's rule for conductivity of mixed electrolyte solutions. The comparison results show that the deviation of a ternary solution from the new conductivity equation is closely related to its isopiestic behavior and that the deviations are often within experimental uncertainty if the examined system obeys the linear isopiestic relation. While larger deviations are found in the system with large ion pairing effect, the predictions can be considerably improved by using the parameters calculated from its isopiestic results. These results imply that the previous formulation of the thermodynamic properties of aqueous solutions of electrolyte mixtures has a counterpart for transport properties.

Densities of the Ternary Systems Y(NO3)3 + Ce(NO3)3 + H2O, Y(NO3)3 + Nd(NO3)3 + H2O, and Ce(NO3)3 + Nd(NO3)3 + H2O and Their Binary Subsystems at Different Temperatures

“…10 However, because the densities of aqueous solutions of (1:3 + 1:3) electrolyte mixtures are not available in the literature to our knowledge, tests were limited to aqueous solutions of (1:1 + 1:1), (1:1 + 1:2), and (1:1 + 1:3) electrolyte mixtures and limited to lower ionic strength. Therefore, in this study the densities were measured for the ternary systems Y(NO 3 …”

“…However, as can be seen from the present results and the previous results, 29 the osmotic coefficients measured at 298.15 K can be used to determine the molalities m M i X i (io) of the binary solutions at other temperatures, which can then be used to provide good predictions for the densities or the surface tensions of the mixed electrolyte solutions in the (293.15 to 308.15) K range and in the (283.15 to 343.15) K range, respectively. Because the osmotic coefficients of the binary electrolyte solutions at 298.15 K have been extensively reported in the literature, the use of the osmotic coefficients of the binary solutions makes the calculations more complicated but exerts little influence on the application of the corresponding equations.ConclusionsDensities were measured for the ternary systems Y(NO3 ) 3 + Ce(NO 3 ) 3 + H 2 O, Y(NO 3 ) 3 + Nd(NO 3 ) 3 + H 2 O,and Ce(NO 3 ) Nd(NO 3 ) 3 + H 2 O and their binary subsystems at (293.15, 298.15, and 308.15) K and then were used to test the predictability of the simple density equations. The comparison results show that eqs 2 and 3 can yield good predictions for the densities of the ternary electrolyte solutions in terms of the properties of the binary solutions that do not involve mixed parameters, which indicates that these equations can make use of the information on the binary solutions, avoiding much complexity in the calculation of densities of the mixed solutions, and provide good predictions for the densities of the mixed solutions.…”

Density and Electrical Conductivity for Aqueous Mixtures of Monoethylene Glycol and Sodium Chloride: Experimental Data and Data-Driven Modeling for Composition Determination

“…Figure shows a comparison of the electrical conductivity measurements presented in this work and values reported in the literature for both water + NaCl and MEG + NaCl mixtures. It is noteworthy that Wang et al also observed that electrical conductivity values reported by Sandengen and Kaasa for water + NaCl mixtures are underestimated in relation to other authors; − see Figure A.…”

Extension of the Simple Equations for Prediction of the Properties of Mixed Electrolyte Solutions to the Mixed Ionic Liquid Solutions

“…The binary aqueous solutions were prepared by mass from double-distilled deionized water and the IL using a Sartorius CT225D balance with a precision of (5 Â 10 -5 g. The molalities of IL stock solutions were also analyzed using AgNO 3 titration. 13 The ternary solutions were prepared by mixing the binary solutions. The uncertainty was (5 Â 10 -5 mol 3 kg -1 .…”

“…The conductivity measurements were carried out with a METLER TOLEDO SevenEasyTM conductivity meter calibrated with standard aqueous potassium chloride solutions. 13 The temperature of the cell was kept constant to within (0.005 K by circulating thermostatted liquid, and the temperature was measured with a calibrated calorimeter thermometer ((0.006 K). 13 Densities of solutions were measured using a KEM oscillatingtube digital densimeter (DA-505) thermostatted to better than (0.01 K. 40,41 The temperature in the measuring cell was monitored with a digital thermometer.…”