The Evaluation of Thermodynamic Parameters of Viscous Flow in Dimethylformamide (DMF)-Water Mixtures for Chlorides and Bromides of Calcium, Strontium and Barium at 25o and 35o C

Abstract

The thennodynamic parameters for viscous flow, viz., ΔE*, ΔF* and   ΔS* at 25° and 35°C have been calculated for the chlorides and bromides   of calcium, strontium and barium in DMF-water mixtures of various   composition using the method of Nightingale and Benck!s equation based   on the application of Eyring's theory of absolute reaction rate. The activation   parameters for viscous flow have been obtained to throw light on the   mechanism of viscous flow. The values for ΔE* and ΔF* increase with the   solvent composition and decrease with the rise of temperature for all   electrolyte solutions. Barium halides cause a larger decrease in ΔE* of   solvent system than the corresponding halides of strontium and calcium at   all solvent composition as well as on both the temperatures. ΔS* value   decreases with solvent composition as well as with the rise of temperature   for all the electrolyte solutions. In the case of solvent,  ΔS*  reaches a   maximum in the vicinity of 20% DMF -water mixture at both the temperatures,   suggesting that the solvent has the highest degree of structure near   this composition.