Analysis of the Molecular Interactions of Potassium Chloride Solutions in N-Methylmorpholine by Physical Methods at Different Temperatures

Abstract

In this study, the densities, r viscosities, h and refractive index, nD were measured for the binary mixtures of N-methylmorpholine and water, in different weight percentages (25%, 50% and 75%) and at three different temperatures 298.15 K, 308.15 K and 318.15 K. The experimental results of the densities, viscosities and refractive index of the binary mixtures of N-methylmorpholine and water, the excess molar volumes, VE excess viscosities, hE and excess refractive index, nE were calculated. the experimental results of the mixtures containing potassium chloride within the concentration range (0.0025-0.1 M), we have found that the potassium chloride is a structure breaker for the mixtures of water and solvent. At the same time potassium chloride increases the molecular interaction between salt ion with water and with solvent as indicated from B-coefficient values of Jones-Dole equation: (hrel - 1) / = A + B where the A-coefficient indicates the interaction between ion-ion, and B-coefficient indicates the interaction between ion and solvent. The study showed that the increasing the concentration of N-methylmorpholine causes decreasing in B-coefficient value and this prove that the salt is a structure maker for mixtures of water with solvent. Calculation of the excess activation energy of viscous flow, DG*, proved that the highest value of activation energy achieved when the mixture contains equal weight (50% : 50%) of water and solvent N-methylmorpholine.

Keywords

• -