Dielectric Relaxation Studies of Binary Mixtures of Ethyl Alcohol and Tetramethylurea in the Benzene Solution from Microwave Absorption Data

Abstract

The dielectric relaxation studies of different molar concentrations of ethanol (C 2 H 5 OH) in the binary mixtures of ethanol and tetramethylurea in benzene solutions have been studied at 9.883GHz by using standard standing microwave techniques and Gopala Krishna's single frequency concentration variation method at different temperatures (25°C, 30°C, 35°C and 40°C). It is found that dielectric relaxation time varies non-linearly with the variation in molar concentration of ethanol in the whole concentration range of the binary mixture. Based upon above results solute-solute and solute-solvent types of molecular association have been proposed. The dielectric relaxation process for 50% mole fraction of ethanol in the binary mixture is found to be an activated process. The energy parameters (ΔH e , ΔF e , AS.) for the dielectric relaxation process of binary mixtures containing 50% mole fraction of ethanol have been calculated at the respective given temperatures. Comparison has been made with the corresponding energy parameters for viscous flow process. It is found that the dielectric relaxation process can be treated as the rate process like the viscous flow process.