1 Journal of Solution Chemistry 41, (3) (2012) 458-474. doi: 10.1007/s10953-012-9812-9 Viscosity Arrhenius activation energy and derived partial molar properties in 1,4- dioxane + water binary mixtures from 293.15 K to 323.15 K. N. Ouerfelli 1, 2,* , Z. Barhoumi 1 , O. Iulian 3 1. Unité de Recherche Physico-Chimie des Matériaux, Département de Chimie, Faculté des Sciences de Tunis, (FST), Campus Universitaire, 2092 El Manar Tunisie. 2. Laboratoire de Chimie Analytique et Electrochimie, Département de Chimie, Faculté des Sciences de Tunis, (FST), Campus Universitaire, 2092 El Manar Tunisie. 3. Department of Applied Physical Chemistry and Electrochemistry, Faculty of Applied Chemistry and Materials Science, University Politehnica of Bucharest, Polizu 1, RO-011061, 060042 Bucharest, Romania. * Corresponding Author: Fax: 21671885008, e-mail: nouerfelli@yahoo.fr (N. Ouerfelli). Abstract The knowledge and predicting of physicochemical properties of binary mixtures is of great importance for understanding intermolecular interactions. The viscosities () has been investigated by using density () and kinematic viscosity () measurements for 1,4-dioxane + water (D-W) mixtures over the entire range of mole fractions under atmospheric pressure and at 311.15 K, 316.15 K and 320.15 K to enrich the studied temperatures range given from literature and to improve investigations. Viscosity Arrhenius activation energy of 1,4-dioxane + water mixtures has been calculated from the experimental results of viscosity measurements and presented in a previous work only for four temperatures and for eleven various temperatures in the present work, over the entire range of composition in the temperatures range from 293.15K to 323.15K. On the basis of partial molar activation energy through Arrhenius viscosity, interactions between water and 1,4-dioxane molecules have been discussed. Comparison between some reduced Redlich-Kister functions in all the domains of compositions shows the existence of two main distinct behaviours. Keywords: Binary liquid mixtures; viscosity; Arrhenius activation energy; 1,4-dioxane; interactions. 1 Introduction Physical and chemical properties of binary liquid mixtures are important for understanding the thermodynamic behaviour and for designing and optimizing industrial processes. This article is a continuation of earlier works that include the study of the 1,4-dioxane + water (D-W) binary liquid mixtures [1-6]. The 1,4-dioxane + water solvent mixture is mostly attractive, and a great deal of work has been well explored by many researchers [7-14] with different detailed experimental studies in order to understand the hydrogen bounding interactions and correlation length between unlike molecules in the cluster formation. The study of physico- chemical properties of systems with 1,4-dioxane and water is important for understanding the influence of the intermolecular interactions. In the frame of scientific research on binary liquid mixtures in chemical, pharmaceutical and foodstuff industries, the study of correlation equations of excess or deviation quantities is very interesting in applied chemistry to predict physicochemical properties in the hydraulic calculations of fluid transport and for energy transference calculations especially for viscosity [15]. Hence, in previous work [5] the viscosity of 1,4-dioxane + water mixtures results have been fitted to the Redlich–Kister (RK) polynomial equation [16,17] and the recently proposed Herráez correlation equation [15] to derive binary coefficients and estimate the corresponding standard deviation between experimental and calculated values. We have noted that, at infinite dilution of 1,4-dioxane in water, the Herráez exponential function’s values converge to a surprising single point (0.5) independent of temperature which is justified [5,6] and considered as an universal exponent characterizing predominant solute-solute interaction at infinite dilution of dioxane in water. In this work we present the study of viscosity and Arrhenius behaviour in 1,4-dioxane + water binary mixtures between 293.15 K and 323.15 K. For this purpose new experimental data of dynamic viscosities () for the binary liquid mixtures of 1,4-dioxane+water at 311.15 K, 316.15 K and 320.15 K have been reported and utilised with data from previous works. The Arrhenius parameters (activation energy and pre-exponential entropic factor) of pure components and of binary mixture are determined as a function of temperature. The excess activation energy (Ea) and the logarithm of the entropic factor deviation ( lnAs) were correlated as reduced RK properties.