Dielectric relaxation studies of binary mixtures of acetone and N-methylacetamide in benzene solution using microwave absorption data

921-925The dielectric relaxation times() and the dipole moments() of the binary mixtures of different molar concentrations of acetone(CH3COCH3) in the binary mixtures of acetone and N-methylacetamide(NMA) in benzene solutions have been calculated by using standard standing wave microwave techniques and Gopala Krishna’s single frequency(9.88GHz) concentration variational method at different temperatures (25, 30, 35, 40°C).The dielectric relaxation process has been found to be an activated process. The energy parameters (H, F, S) for the dielectric relaxation process of binary mixtures containing 30% mole-fraction of acetone have been calculated at the respective given temperatures and the comparison has been made with the corresponding energy parameters (H, F, S) for the viscous flow. On the basis of the observations, it is found that the dielectric relaxation process can be treated as the rate process like the viscous flow process. The solute-solute and solute-solvent molecular associations have been predicted

Dielectric relaxation studies of binary mixtures of acetone and N, N-dimethylacetamide in the benzene solutions using microwave absorption data

630-633<span style="font-size: 15.0pt;mso-bidi-font-size:8.0pt;font-family:" times="" new="" roman","serif""="">Using standard standing wave microwave techniques and following Gopala Krishna's [Trans Faraday Soc, 33 (1957) 767] single frequency (9 .88 GHz) concentration variational method, the dielectric relaxation times (τ<span style="font-size:14.5pt;mso-bidi-font-size: 7.5pt;font-family:" arial","sans-serif""="">) <span style="font-size:15.0pt; mso-bidi-font-size:8.0pt;font-family:" times="" new="" roman","serif""="">and the dipole moments (μ) of the binary mixtures of different molar concentrations of acetone (Ac) in binary mixtures of acetone and N,N-dimethylacetamide in benzene solutions have been calculated at different temperatures (25, 30, 35 and 40 °C. The energy parameters <span style="font-size:15.5pt;mso-bidi-font-size: 8.5pt;font-family:" times="" new="" roman","serif""="">(ΔHƐ , ΔFƐ<span style="font-size:15.5pt;mso-bidi-font-size: 8.5pt;font-family:" arial","sans-serif""="">,<span style="font-size: 15.5pt;mso-bidi-font-size:8.5pt;font-family:" times="" new="" roman","serif""=""> ΔSƐ) for the dielectric relaxation process of binary mixtures containing 50% mole fractions of Ac have been calculated, at the respective given temperatures. Comparison has been made with the corresponding energy parameters for viscous now. From the observations, it is found that the dielectric relaxation process like the viscous now process can be treated as the rate process. On the basis of above studies, solute-solvent type of the molecular association can be predicted. </span

Dielectric relaxation study of binary mixtures of ethyl alcohol and N, N-dimethylformamide in benzene solution from microwave absorption data

163-167Dielectric constant (Ɛ′) and dielectric loss (Ɛ″) of ethanol (C₂H₅OH) and binary mixtures of ethanol and N, N-dimethylformamide (DMF) in benzene solutions have been measured at microwave frequency 9.883 GHz at different temperatures 25, 30, 35 and 40ºC. Standing microwave techniques and Gopala Krishna’s [Trans Faraday Soc, 33 (1957)767.] single frequency concentration variation method have been used for above measurements. The measured values of Ɛ′ and Ɛ″ have been used to evaluate dipole moment (μ) and relaxation time (). Various thermodynamic parameters (ΔH ΔFand ΔS) for the dielectric relaxation process of binary mixtures containing 50% mole fraction of OH have been calculated using Eyring’s rate equations. 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. Non-linear variation of relaxation time with molar concentration of ethanol in the whole concentration range of the binary mixture indicates the existence of solute-solute type of molecular association