lUlm ELSEVIER Fluid Phase Equilibria 123 (1996) 271-281 Excess enthalpies and volumes of mixing of 1-propanol or 2-propanol + cyclohexane at 298.15 and 308.15 K K.C. Singh *, K.C. Kalra, Sanjeev Maken, Vibha Gupta Department of Chemistry, Maharshi Dayanand University, Rohtak-124001, India Received25 January 1995; accepted 11 January 1996 Abstract Excess molar enthalpies and excess molar volumes at 298.15 and 308.15K are reported for 1-propanol or 2-propanol with cyclohexane. The analysis in terms of Mecke-Kempter association model with a Flory contribution term and generalized quasi-lattice model by Barker is described. Keywords: Excess volume; Excess enthalpy; Mecke-Kempter model; Barker theory; Association I. Introduction The interpretation of the thermodynamic properties of solutions of alcohols in non-polar solvents has generally been made in terms of association of alcohol molecules through hydrogen bonding (Savini et al., 1965; Renon and Prausnitz, 1967; Van Ness et al., 1967; Stokes and Burfitt, 1973; Marsh and Burfitt, 1975) and of complex formation (Fletcher and Heller, 1967;Fletcher, 1969; Stokes and Marsh, 1976) between alcohol and solvent molecules. Lattice model theories of associated mixtures (Nath and Bender, 1981; Brandani, 1983; Treszczanowicz and Benson, 1985; Brandani and Evangelista, 1987) have been attempted to describe their behaviour. It has been found that the excess properties of mixtures formed from an alkanol with alkane could be correlated quite well by an association model of Mecke-Kempter (MK) type with an added Flory contribution term (Treszc- zanowicz and Benson, 1985). The use of generalized quasi-lattice theory described by Barker (Barker, 1952) to calculate the thermodynamic properties of mixing of associated solution has also been successful (Goates et al., 1962; Nigam et al., 1980). In the present work we report the experimental results of H E and V E of 1-propanol or 2-propanol + cyclohexane at 298.15 and 308.15 K and their interpretation in terms of anMK type of association model (Treszczanowicz and Benson, 1985) and quasi-lattice theory by Barker (Barker, 1952). * Corresponding author. 0378-3812/96/$15.00 Copyright © 1996 Elsevier Science B.V. All rights reserved. PII S0378-3812(96)03016-6