Conductivities of alkali metal perchlorates in ethylene glycol at 25°C

Abstract

The conductivities of NaClO₄, KClO₄, RbClO₄ and CsClO₄ in ethylene glycol at 25°C were determined and the temperature coefficients of their mobilities estimated. These data, together with those for other electrolytes in the same solvent, were analysed to obtain the association constants and the limiting molar conductivities of the electrolytes. The analysis shows that alkali metal ions are strongly solvated in ethylene glycol. The salts of the large tetra-alkylammonium ions are definitely associated, and the values of the association constants are larger than expected for purely electrostatic ion-pairing. This type of behaviour, which has been observed in other protic solvents, depends on the intermolecular hydrogen bonding of the solvent molecules. Large alkali metal ions appear to be structure-breaking ions in ethylene glycol as well as in water.