Thermodynamic Study of Ternary Mixtures Containing 1-Methyl Pyrrolidin-2-one,Propan-2-ol and Benzene or Methyl Benzene or Cyclohexane

Densities, ρ ₁₂₃, and speeds of sound, u ₁₂₃, of 1-methyl pyrrolidin-2-one (1) + benzene or methyl benzene or cyclohexane (2) + propan-2-ol (3) ternary mixtures have been measured over the entire composition range at 308.15 K and atmospheric pressure. The resulting ρ ₁₂₃ and V₁₂₃^EV_{123}^{\mathrm{E}} data were utilized to predict excess isentropic compressibilities, (k_S^E)₁₂₃(\kappa_{S}^{\mathrm{E}})_{123}, of the studied (1+2+3) mixtures. The observed V₁₂₃^EV_{123}^{\mathrm{E}} and (k_S^E)₁₂₃(\kappa_{S}^{\mathrm{E}})_{123} data have been analyzed in terms of Graph theory (which involved the topology of a molecule). It has been observed that V₁₂₃^EV_{123}^{\mathrm{E}} and (k_S^E)₁₂₃(\kappa_{S}^{\mathrm{E}})_{123} values determined by Graph theory compare well with their corresponding experimental values.     

Excess Molar Volumes, Excess Molar Enthalpies and Excess Isentropic Compressibilities of 1-Methyl Pyrrolidin-2-one with Water and Propanols

Excess molar volumes V ^E, excess molar enthalpies H ^E, and speeds of sound u for 1-methyl pyrrolidin-2-one (1) + water or propan-1-ol or propan-2-ol (2) binary mixtures have been measured over the entire composition range (at 308.15 K) using a dilatometer, calorimeter and interferometer. Speeds of sound data, u, of (1 + 2) binary mixtures have been utilized to determine excess isentropic compressibilities, $ \kappa_{S}^{\text{E}} $ . The observed V ^E, H ^E and $ \kappa_{S}^{\text{E}} $ data have been analyzed in terms of (1) Graph theory (which involves the topology of the constituents of mixture), and (2) the Prigogine–Flory–Patterson theory. Analysis of V ^E data in terms of Graph theory suggests that 1-methyl pyrrolidin-2-one, water, propan-1-ol, and propan-2-ol exist as associated molecular entities. IR studies lend additional support to the proposed molecular entities in (1 + 2) mixtures. It has been observed that V ^E, H ^E and $ \kappa_{S}^{\text{E}} $ values predicted by Graph theory compare well with their corresponding experimental values.