Novel Model for Predicting the Electrical Conductivity of Multisalt Electrolyte Solutions

Abstract

This study presents a novel model to predict the electrical conductivity of multisalt electrolyte solutions by incorporating corrections to the ideal behavior due to relaxation and electrophoretic effects. The performance of the model is evaluated by comparing its predictions with the experimental data of 24 multisalt aqueous solutions. The comparison reveals good agreement for solutions with an ionic strength below 1 mol/L without adjusting any parameter to fit to the experimental data. However, the model tends to overestimate the molar conductivity at higher ionic strengths. The discrepancy is attributed to the neglect of the solvent structure and the formation of ion pairs. It has been speculated how the accuracy of the developed model could be improved in relation to these limitations. Furthermore, the performance of the model is rigorously tested in systems with ion complex formation. It has been demonstrated that when the distribution of ion complexes is calculated from a thermodynamic model and then used to predict the electrical conductivity with the developed model, a satisfactory level of accuracy is attained for these systems.

Simplified Universal Equations for Ionic Conductivity and Transference Number

“…Recently, a novel method for predicting the electrical conductivity of multisalt electrolyte solution has been proposed by incorporating modifications in the relaxation as well as electrophoretic effects. 15 This model works well for ionic strength below 1 mol l −1 . In contrast, it overpredicts conductivity at higher ionic strength.…”