Thermodynamics Research Center / ThermoML | Journal of Chemical Thermodynamics

The contour of excess molar enthalpy at a mole fraction of benzene x = 0.548 on the p-T plane in liquid state and near the critical points for the (benzene + cyclohexane) mixture

Fang, G.S., Tsukamoto, K., Maebayashi, M., Ohba, M.
J. Chem. Thermodyn. 2018, 120, 33-38
ABSTRACT
The excess molar enthalpy HE m(x = 0.548) of the {x benzene + (1 x) cyclohexane} mixture was measured near the vapour pressure curve of benzene, and was measured in the intermediate region between the liquid state and the state near the critical points. The contour of HE m(x = 0.548) was created on the p-T plane over a wide range of temperature and pressure including near the critical points. A valley was observed for the HE m(T, p, x = 0.548) surface in the intermediate region between the liquid state and the state near the critical points. The HE m(x = 0.548) smoothly decreased on the high-temperature side of the valley as temperature and pressure increased, and dramatically increased in this region as the temperature and pressure approached the critical points. Near these critical points, the HE m(T, p, x = 0.548) surface had two ridges, which extended the vapour pressure curves of benzene and cyclohexane. Finally, it was observed that near the critical point of benzene, HE m(x = 0.548) reached a local maximum at a temperature and pressure slightly less than the critical point of benzene.
Compounds
# Formula Name
1 C6H6 benzene
2 C6H12 cyclohexane
Datasets
The table above is generated from the ThermoML associated json file (link above). POMD and RXND refer to PureOrMixture and Reaction Datasets. The compound numbers are included in properties, variables, and phases, if specificied; the numbers refer to the table of compounds on the left.
Type Compound-# Property Variable Constraint Phase Method #Points
  • POMD
  • 1
  • 2
  • Excess molar enthalpy (molar enthalpy of mixing), kJ/mol ; Liquid
  • Temperature, K; Liquid
  • Pressure, kPa; Liquid
  • Mole fraction - 1; Liquid
  • Liquid
  • Flow calorimetry
  • 95
  • POMD
  • 1
  • 2
  • Excess molar enthalpy (molar enthalpy of mixing), kJ/mol ; Fluid (supercritical or subcritical phases)
  • Pressure, kPa; Fluid (supercritical or subcritical phases)
  • Temperature, K; Fluid (supercritical or subcritical phases)
  • Mole fraction - 1; Fluid (supercritical or subcritical phases)
  • Fluid (supercritical or subcritical phases)
  • Flow calorimetry
  • 31