Studies on the importance of thermodynamic and transport properties of liquid mixtures at various temperatures

Abstract

Densities (ρ), speeds of sound (u) and viscosities (η) are reported for binary mixtures of 2-methoxyaniline with carboxylic acids (ethanoic acid, propanoic acid and butanoic acid) over the entire composition range of mole fraction at T = (303.15–318.15) K and at atmospheric pressure 0.1 MPa. The excess properties such as excess molar volume, excess isentropic compressibility and deviation in viscosity are calculated from the experimental density, speed of sound and viscosity. Excess properties are correlated using the Redlich–Kister polynomial equation. The excess partial molar volumes and excess partial molar isentropic compressibilities are calculated for all the binary systems throughout the composition range and at infinite dilutions. The results are analyzed in terms of dipole–dipole interactions and hydrogen bonding between 2-methoxyaniline and carboxylic acid molecules. The VE results are analyzed in the light of Prigogine–Flory–Patterson theory. Analysis of each of the three contributions, viz interactional, free volume and P* to VE, has shown that interactional contribution is positive for all systems, and the free volume and P* contributions are negative for all the binary mixtures. A good agreement is obtained between excess quantities and spectroscopic data.