The Water–18-Crown-6 System: Experimental Investigation and Thermodynamic Modeling

Abstract

Vapor pressures of binary aqueous solutions containing 18-crown-6 over a wide concentration range up to saturation were measured at (293.15 and 298.15) K, and activities of solvent were calculated. Melting enthalpies of 18-crown-6 octa- and dodecahydrates have been determined by the differential scanning calorimetry (DSC) method. The new experimental data and previously published literature data (activities of water, enthalpies of dilution, and solubility data) were used for thermodynamic modeling of the water–18-crown-6 system. As a result the phase diagram of the water–18-crown-6 system was constructed using the universal quasichemical (UNIQUAC) expression for the excess Gibbs energy of the liquid phase.

A Water–Urea–Ammonium Sulfamate system: Experimental investigation and thermodynamic modelling

“…Vapor-liquid equilibria data for the H 2 OeASM and H 2 OeASMeUr systems were obtained by the static method at 298.15 K. A detailed description of the apparatus and the measurement technique was given previously by Kovalenko et al [11]. The vapor pressure apparatus consists of two parts: the degassing block and the pressure measuring system.…”

Phase Equilibria and Thermodynamic Properties in the Zinc Chloride–Zinc Methanesulfonate–Water System

“…Since one volatile component (water) was present in the system, the determined vapor pressure corresponded to its partial vapor pressure at equilibrium. The measurement of saturated vapor pressure was carried out by the static method at temperatures of 15, 25, and 35 °C (288.15, 298.15, and 308.15 K) at a facility created earlier in the laboratory of Chemical Thermodynamics (the device was described in detail in the work of Kovalenko et al 19 ).…”