Viscosities of tetrabutylammonium bromide, sodium tetraphenylborate and sodium bromide in 2-ethoxyethanol plus water mixed solvent media at 308.15, 313.15, 318.15 and 323.15 K

摘要

The viscosities of the solutions of tetrabutylammonium bromide (Bu4NBr), sodium tetraphenylborate (NaBPh4), sodium bromide (NaBr) in 2-ethoxyethanol+water mixed solvent media containing 0.25, 0.50 and 0.75 mass fractions of 2-ethoxyethanol (w(1)) have been reported at 308.15, 313.15, 318.15, and 323.15 K. The viscosity data have been analyzed by the Jones-Dole equation for the associated electrolytes to evaluate the viscosity B-coefficients of the electrolytes. These data have also been analyzed by the transition-state treatment to obtain contribution of the solutes to the free energy of activation for viscous flow of the solution. The viscosity of the solvent is found to be greatly modified by the presence of the tetrabutylammonium, tetraaphenylborate and bromide ions; sodium ion, on the other hand, is not such efficient in modifying the viscosity of the media investigated. Moreover, these ions behave neither as structure-breaker nor as structure-maker and the formation of the transition-state is made less favorable in their presence in aqueous 2-ethoxyethanol solutions. (C) 2007 Elsevier B.V. All rights reserved.