A study of activation parameters for viscous flow process of some tetraalkylammonium salts in binary mixtures of <i>N, N</i>-dimethylformamide and ethyl methyl ketone

Abstract

Viscosities and densities of tetrabutylammoniumtetraphenylammonium boride (Bu₄NBPh₄), tetrabutylammonium bromide (Bu₄NBr), tetrapentylammonium bromide (Pen₄NBr), tetrahexylammonium iodide (Hex₄NI), sodium tetraphenyl boride (NaBPh₄) and sodium iodide (NaI) in ethyl methyl ketone (EMK), N, N-dimethyl foramide (DMF) and EMK+DMF solvent mixtures containing 0, 20, 40, 60, 80 and 100 mol % of EMK in the concentration range (0.02-0.1) mol dm^-3 at 25, 35, and 45°C have been reported. The viscosity data have been analyzed in terms of A- and B- viscosity coefficients of the Jones-Dole equation. Both A- and B-coefficients have been found to be positive over the en tire solvent composition range at all temperatures. The B-coefficients have been resolved into B± ionic coefficients using Bu₄NBPh₄ assumptions. The B± values of telraalkylammonium ions are found to be positive. Partial molal volumes (<i>V</i>^o2) have also been calculated which have been used along with B-values to calculate activation parameters for viscous flow process of electrolytic solutions. The activation parameters have been examined as a function of solvent composition to interpret the solution behaviour of these tetraalkylammonium salts in EMK-DMF mixtures.