www.wjpps.com Vol 6, Issue 10, 2017. 857 Revathi et al. World Journal of Pharmacy and Pharmaceutical Sciences A STUDY ON THERMODYNAMIC PROPERTIES OF BINARY LIQUID MIXTURES OF DIETHYLMALONATE WITH TOLUENE AND CHLOROBENZENE AT 308.15K AND 318.15K U. Revathi* 1 , K. Uma Sivakami 1 , P. Prabhu 1 and A. Rose Venis 1 Department of Chemistry, St. Joseph’s College, Tiruchirappalli, Tamil Nadu, India. ABSTRACT The excess molar volume (V E ), viscosity (η), viscosity deviation (Δη), adiabatic compressibility (ΔK S ) and free volume (V f ) of binary liquid mixtures for Diethylmalonate with toluene and chlorobenzene were measured 308.15K and 318.15K. The intermolecular interactions between the molecules were explained from the above experimental data. KEYWORDS: Density, viscosity, excess volume, velocity, diethylmalonate, binary mixtures. INTRODUTION Thermodynamic behaviors of binary liquid mixtures provide [1-3] information about the molecular interactions. Accurate knowledge of thermodynamic property of binary liquid mixtures has been used in various field of research and the properties are used in to serve many engineering process. Diethylmalonate is used in pharmaceutical industry [4,5] and in the synthesis of chloroquine. It can also be used in various industries, such as pesticides [6,7] , paints, etc. The molecular interaction [8] between the binary liquid mixture of diethylmalonate with toluene and chlorobenzene have been explained by calculating thermodynamic properties, such as density, viscosity, ultrasonic velocity at two different temperatures 308.15K & 318.15K over a wide range of different mole fraction. From the above measuring data the acoustical properties, such as excess molar volume (V E ), viscosity (η), viscosity deviation (Δη), Adiabatic compressibility (ΔK S ) and free volume (V f ) have been calculated. WORLD JOURNAL OF PHARMACY AND PHARMACEUTICAL SCIENCES SJIF Impact Factor 6.647 Volume 6, Issue 10, 857-865 Research Article ISSN 2278 – 4357 Article Received on 30 July 2017, Revised on 20 August 2017, Accepted on 10 Sept. 2017, DOI: 10.20959/wjpps201710-10206 *Corresponding Author U. Revathi Department of Chemistry, St. Joseph’s College, Tiruchirappalli, Tamil Nadu, India.