DIELECTRIC-RELAXATION STUDIES OF MIXTURES OF DIMETHYLSULFOXIDE AND N,N-DIMETHYLFORMAMIDE IN CARBONTETRACHLORIDE SOLUTION USING MICROWAVE-ABSORPTION TECHNIQUES

Single frequency concentration varitional method of Gopalakrishana has been used to calculate dielectric relaxation times (tau) and dipole m oment (mu) for dilute solutions of binary mixtures of dimethylsulphoxi de (DMSO) and N,N-dimethylformamide (DMF) in carbontetrachloride (CCl4 ) solution at 25, 30, 35 and 40 degrees C. These measurements have bee n made at 9.174 GHz. The energy parameters (Delta F-epsilon, Delta H-e psilon, Delta S-epsilon) for the dielectric relaxation for (DMSO + DMF ) mixtures containing 0.2 mole of DMSO have been calculated at 25, 30, 35 and 40 degrees C and compared with the corresponding viscosity par ameters. Based on these studies, it is inferred that dielectric relaxa tion process like viscous flow process can be treated as a rate proces s. From relaxation behaviour of DMSO and DMF binary mixtures in CCl4 s olution, solute-solute and solute-solvent types of associations are pr oposed.