The Temperature Dependence of the Properties of Electrolyte Solutions. III. Conductance of Various Salts at High Concentrations in Propylene Carbonate at Temperatures from — 45°Cto +25°C

Elektrochemie I Losungen I Transporterscheinungen Specific conductances of E t 4 N P F 6 , P r 4 N P F 6 , Bu 4 NPF 6 , L iPF 6 , K P F 6 , LiC10 4 , and K S C N in propylene carbonate were studied at high concentrations in the temperature range from + 2 5 ° C to — 4 5 ° C Data are fitted by a least-squares method to a four-parametric empirical equation, yielding the maximum specific conductance KMAX and the corresponding concentration fi. Within the frame-work of a hydrodynamic model the Stokes-radii of the ions and the solvent viscosity are found to be the most important conductance-determining parameters, affecting both K M M and fi. Ionic association in solutions with propylene carbonate as the solvent is not of significant importance. Kinetic treatment of conductance yields temperature-dependent activation energies, but at any one temperature equal for all salts at concentration ^.