Excess molar enthalpies of ethane-1,2-diamine plus primary and secondary alkanols (C1–C4) and correlation with Redlich-Kister, Wilson, NRTL and UNIQUAC models at T = 298 K

Abstract

Excess molar enthalpies, HmE of binary mixtures of ethane-1,2-diamine (EDA) with methanol, ethanol, propan-1-ol, propan-2-ol, butan-1-ol and butan-2-ol were calculated from calorimetric data at T=298K and atmospheric pressure (81.5kPa) with a Parr 1455 solution calorimeter. All the binary mixtures showed exothermic behavior over the entire range of compositions. From the experimental results, the excess partial molar enthalpies, HiE and excess partial molar enthalpies at infinite dilution, HiE,∞ were calculated. Excess molar enthalpies, HmE values increase as the chain length of the alkanol is increased, showing minimum values varying from −4395 (methanol) to −1987 J·mol-1 (butan-2-ol). The minimum HmE values were observed about 0.4mol fraction of ethane-1,2-diamine (EDA). The experimental results were discussed in terms of intermolecular interactions, particularly hydrogen-bonding interactions between like and unlike molecules. Finally the experimental results were correlated by the Redlich–Kister equation and the three thermodynamic models (Wilson, NRTL, and UNIQUAC) based on the local composition theory.