ABSTRACT

Enthalpies of solution of urea (U) and tetramethylurea (TMU) in formamide (FA) and ethylene glycol (Eg) have been experimentally determined from (288 to 328) K. Standard enthalpies and heat capacities of solution of non-electrolytes have been computed and compared with those for aqueous solutions. Heat capacities of solution of U and TMU are rather small and positive for both non-aqueous solvents, whereas in cold water the deltaCp0 values for U and TMU reveal different signs. Our comparative analysis indicates that the behavior of both hydrophilic and hydrophobic species in water differs from that in the non-aqueous solvents with the three dimensional H-bond network, according to our experimental results formamide being a more "water-like" solvent than ethylene glycol.

Compounds

#	Formula	Name
1	CH4N2O	urea
2	C5H12N2O	tetramethylurea
3	CH3NO	formamide
4	C2H6O2	1,2-ethanediol
5	H2O	water

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 5	Molar enthalpy of solution, kJ/mol ; Liquid	Temperature, K; Liquid Pressure, kPa; Liquid Mole fraction - 1; Liquid		Liquid	ISOPERIBOL	1
POMD	1 4	Molar enthalpy of solution, kJ/mol ; Liquid	Molality, mol/kg - 1; Liquid Temperature, K; Liquid	Pressure, kPa; Liquid	Liquid	ISOPERIBOL	25
POMD	1 3	Molar enthalpy of solution, kJ/mol ; Liquid	Molality, mol/kg - 1; Liquid Temperature, K; Liquid	Pressure, kPa; Liquid	Liquid	ISOPERIBOL	25
POMD	2 4	Molar enthalpy of solution, kJ/mol ; Liquid	Molality, mol/kg - 2; Liquid Temperature, K; Liquid	Pressure, kPa; Liquid	Liquid	ISOPERIBOL	25
POMD	2 3	Molar enthalpy of solution, kJ/mol ; Liquid	Molality, mol/kg - 2; Liquid Temperature, K; Liquid	Pressure, kPa; Liquid	Liquid	ISOPERIBOL	25
POMD	2 5	Molar enthalpy of solution, kJ/mol ; Liquid	Temperature, K; Liquid Pressure, kPa; Liquid Mole fraction - 2; Liquid		Liquid	ISOPERIBOL	1

Thermodynamics Research Center / ThermoML | Journal of Chemical Thermodynamics

Enthalpies and heat capacities of solution of urea and tetramethylurea in water, ethylene glycol and formamide

Kustov, Andrey V., Smirnova, Nataliya L., Antonova, Olga A.

ABSTRACT