Electrical Conductances of Some Alkali-Metal Salts in N,N-Dimethylacetamide–Water Mixture at 25 °C

Abstract

Abstract Precise measurements on electrical conductances of the solutions of lithium chloride (LiCl), lithium bromide (LiBr), lithium iodide (LiI), lithium perchlorate (LiClO4), lithium tetrafluoroborate (LiBF4), sodium bromide (NaBr), sodium tetraphenylborate (NaBPh4), potassium bromide (KBr), rubidium bromide (RbBr), cesium bromide (CsBr) and tetrabutylammonium bromide (Bu4NBr) in N,N-dimethylacetamide + water (50 v/v) mixture have been reported at 25 °C in the concentration range 0.02–0.05 mol dm−3. The conductance data have been analyzed by the 1978 Fuoss conductance–concentration equation in terms of the limiting molar conductance (Λ0), the association constant (K A) and the association diameter (R). The limiting ionic conductances (λ0 ±) have been estimated from the appropriate division of the limiting molar conductivity value of the “reference electrolyte” tetrabutylammonium tetraphenylborate (Bu4NBPh4). The electrolytes investigated here are found to be significantly dissociated in this solvent medium and all ions remain unsolvated in N,N-dimethylacetamide + water (50 v/v) mixed solvent system with exception of the lithium ion where significant solvation has been noticed. The results have been interpreted in terms of the specific constitutional and structural factors of the solvent and of the solute ions.