Excess molar enthalpies and excess molar volumes of formamide + 1-propanol or 2-propanol and thermodynamic modeling by Prigogine–Flory–Patterson theory and Treszczanowicz–Benson association model

Abstract

Excess molar enthalpies (HmE) at 298.15K and 308.15K and excess molar volumes (VmE) at 308.15K for formamide (1)+1-propanol or 2-propanol (2) mixtures have been measured over the entire composition range. The excess enthalpies and excess volumes data have been utilized to study the thermodynamics of molecular interactions in terms of Prigogine–Flory–Patterson theory and Treszczanowicz–Benson association model with a Flory contribution term. In this paper, this Treszczanowicz–Benson association model was applied, for the first time, to binary mixtures containing both components associated (propanol and formamide) through hydrogen bonding. In both the cases, when either of formamide or propanol was assumed to be associated, the calculated HmE and VmE values compared well with corresponding experimental data. Extent of inter-molecular H-bonding in formamide and propanol in their binary mixtures was also reflected in their molar enthalpy of association of H-bonding ΔhH0 and association constant KH.