Thermodynamics Research Center / ThermoML | Journal of Chemical and Engineering Data

Standard Enthalpies and Heat Capacities of Solution of Urea and Tetramethylurea in Water

Kustov, A. V.[Andrey V.], Smirnova, N. L.[Nataliya L.]
J. Chem. Eng. Data 2010, 55, 9, 3055-3058
ABSTRACT
This paper presents the results of accurate measurements of the enthalpies of solution of a typical hydrophilic solute, urea, and its hydrophobic derivative, tetramethylurea, in water in the temperature range of (278.15 to 338.15) K. The standard enthalpies and heat capacities of solution are computed and compared with available literature values. Our results do indicate that the standard heat capacity of the solution of urea is very small, but it changes its sign at about the temperature minimum of the water heat capacity at constant pressure, while the heat capacity of tetramethylurea solution in water is large, positive, and independent of the temperature.
Compounds
# Formula Name
1 ClK potassium chloride
2 H2O water
3 C3H8O propan-1-ol
4 CH4N2O urea
5 C5H12N2O tetramethylurea
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
  • Molar enthalpy of solution, kJ/mol ; Liquid
  • Temperature, K; Liquid
  • Molality, mol/kg - 1; Liquid
  • Pressure, kPa; Liquid
  • Liquid
  • CALVET:UFactor:0.5
  • 1
  • POMD
  • 3
  • 2
  • Molar enthalpy of solution, kJ/mol ; Liquid
  • Temperature, K; Liquid
  • Pressure, kPa; Liquid
  • Molality, mol/kg - 3; Liquid
  • Liquid
  • OTHER:UFactor:0.5:sMethod:Ampoule calorimetery
  • 1
  • POMD
  • 4
  • 2
  • Molar enthalpy of solution, kJ/mol ; Liquid
  • Temperature, K; Liquid
  • Molality, mol/kg - 4; Liquid
  • Pressure, kPa; Liquid
  • Liquid
  • CALVET:UFactor:0.5
  • 48
  • POMD
  • 5
  • 2
  • Molar enthalpy of solution, kJ/mol ; Liquid
  • Temperature, K; Liquid
  • Molality, mol/kg - 5; Liquid
  • Pressure, kPa; Liquid
  • Liquid
  • CALVET:UFactor:0.5
  • 66