Experimental and theoretical study on excess molar enthalpy of binary mixtures containing isobutanol (1) + alkan-1-ols (C1–C4) (2) at T = 298.15 K

Abstract

Experimental excess molar enthalpies HmE, of binary mixtures containing isobutanol+alkan-1-ols, namely methanol, ethanol, propan-1-ol and butan-1-ol, have been determined as a function of composition at ambient pressure and T=298.15K using a 1455 Parr solution calorimeter. The Redlich–Kister and SSF polynomial equations were used to correlate HmE. The excess partial molar enthalpies, Hm,iE, were also calculated according to experimental excess molar enthalpies and Redlich–Kister polynomial equation. The experimental values of HmE are positive for binary mixtures and their deviations from ideal behavior decrease while the chain length of alkan-1-ols enhances. The extracted data were used to evaluated the so-called intermolecular interaction functions, ∂Hm,iE/∂xi and ∂Hm,iE/∂xj. Three thermodynamic models (Wilson, NRTL, and UNIQUAC) based on the local composition theory were also examined for the suitability by correlating HmE and results were in good agreement with experimental data.