Dielectric Relaxation Studies of Mixtures of N-Methylacetamide and Ethanol in Benzene Solutions Using Microwave Absorption Technique

Abstract

Using standard standing wave microwave X-band techniques, and by following Gopala Krishna's single frequency (9.90 GHz) concentration variational method, the dielectric relaxation times (τ) and dipole moments (µ) of binary mixtures of different molar concentrations of ethanol (EtOH) in binary mixtures of N-methylacetamide (NMA) and ethanol in benzene solutions at 25, 30, 35 and 40 • C have been calculated. The activation parameters (∆H ε , ∆F ε , ∆S ε ) for the dielectric relaxation process of binary mixtures containing 30 mol% of EtOH have been calculated at 25, 30, 35 and 40 • C and compared with the corresponding viscosity parameters. A good agreement between the free energy of activation from these two sets of values shows that the dielectric relaxation process, like the viscous flow, can be treated as a rate process. From relaxation time behaviour of NMA and EtOH binary mixtures in benzene solution, solute-solute and solute-solvent types of the molecular association have been predicted.

Microwave Dielectric behaviour of ketones in solution state at a constant temperature

“…Ethylmethyl ketone (EMK) is an important organic compound (CH 3 C(O)CH 2 CH 3 ) having moderate dielectric constant and dipolemoment =2.78D in the vapour phase. Dielectric relaxation studies of polar molecules in non-polar solvent using microwave absorption techniques have been studied by many researchers [3][4][5][6][7][8].The measurement have been made for the binary mixture of different mole-fraction of acetone and EMK at constant temperate 303K. The dielectric relaxation process has been found using Higasi's method.…”