Electrical conductances for some tetraalkylammonium bromides, lithium tetrafluoroborate and tetrabutylammonium tetrabutylborate in propylene carbonate at 25 °C
Abstract
Conductance measurements are reported for several symmetrical tetraalkylammonium bromides, lithium tetrafluoroborate (LiBF4) and tetrabutylammonium tetrabutylborate (Bu4NBBu4) in propylene carbonate (PC) at 25 °C. The data have been analysed by the 1978 Fuoss conductance equation in terms of the limiting molar conductivity, Λo, the association constant, KA, and the association distance R. The single-ion conductances have been determined from the Λo value of Bu4NBBu4 using it as a ‘reference electrolyte’. The results indicate that with the exception of LiBF4 to some extent, other salts are almost unassociated in this solvent medium. The evaluation of Stokes radii of the ions indicate that Li+ is extensively solvated while the other ions remain almost unsolvated. The results have been discussed in terms of the ion-solvating ability of PC and also compared with the previous values in this system.