The Relative Reduced Redlich–Kister Equations for Correlating Excess Properties of N,N-Dimethylacetamide + Water Binary Mixtures at Temperatures from 298.15 K to 318.15 K

Abstract

Excess molar volumes, viscosity deviations, and isentropic compressibility changes in N,N-dimethylacetamide + water binary mixtures at (298.15, 308.15 and 318.15) K were calculated from experimental density, viscosity and sound velocity results presented in previous work. Here these experimental values were used to test the applicability of the correlative reduced Redlich–Kister equation and the recently proposed Herraez equation, as well as their corresponding relative functions. Their correlation ability at different temperatures, and the use of different numbers of parameters, are discussed for the case of limited experimental data. The relative functions are important to reduce the effect of temperature and, consequently, to reveal the effects of different types of interactions. Values of the limiting excess partial molar volume at infinite dilution were deduced using different methods. Also, the activation parameters and partial molar Gibbs energy of activation of viscous flow were analyzed as functions of composition. Correlation between the two Arrhenius parameters of viscosity in all composition domains show the existence of two distinct behaviors, separated by a stabilized structure over a short range of mole fractions from (0.2 to 0.3) in N,N-dimethylacetamide. In this regard, a correlation equation recently proposed by Belda has also been applied to the present system for deriving molar volume properties, in order to assess the validity of the proposed equation,