Additive Effect of 1-Propanol and 2-Propanol on Molecular Organization of H2O in the Water-Rich Region: Excess Chemical Potential, Partial Molar Enthalpy and Volume of 1-Propanol in 1-Propanol–2-Propanol–H2O at 25 °C

Abstract

Abstract Excess chemical potential, μ1PE, partial molar enthalpy, H1PE and volume of 1-propanol, V1PE, were determined as a function of mole fraction of 1-propanol, x1P, in mixed solvents of aqueous 2-propanol with various initial mole fraction of 2-propanol, x2P0. The 1-propanol–1-propanol interaction functions, H1P–1PE ≡ N(∂H1PE/∂n1P), and V1P–1PE ≡ N(∂V1PE/∂n1P), were evaluated by graphical differentiation. The x1P-dependence of all these quantities indicates that 1-propanol and 2-propanol modify the molecular organization of H2O in the same and additive manner in the water-rich region. The additive effect of 1-propanol and that of 2-propanol are in the ratio of (0.07/0.08).