Electrical Conductivities of 1:1 Electrolytes in High-Temperature Methanol

Abstract

Molar ionic conductivity is one of the most basic properties characterizing the dynamic prcesses in electrolyte solutions. The sphere-in-continuum model is an important and useful framework for the theoretical calculation of ionic conductivity. So far, however, the validity and limitations of the continuum model have been examined only at thermodynamic conditions near ambient one. In this work, we review recent conductivity measurements of 1:1 electrolytes in high-temperature methanol, and discuss the application limit of the continuum model in the density region lower than the ambient one. For small monatomic ions, the continuum theory well explains the density dependence of conductivity at densities above 2ρ_c, where ρ_c is the critical density. For larger monatomic ions, we can recognize shortcomings of the continuum theory in ambient conditions, while the agreements between theory and experiment are improved by decreasing density down to 2ρ_c. At densities lower than 2ρ_c, the continuum theory is not successful in explaining the experimental conductivities.