Isotope effects in aqueous systems. Excess thermodynamic properties of 1,3-dimethylurea solutions in H{sub 2}O and D{sub 2}O
- Atomic Energy Research Inst., Budapest (Hungary)
- Univ. of Tennessee, Knoxville, TN (United States). Chemistry Dept.
The osmotic coefficients of 1,3-dimethylurea-h{sub 2}(DMUh{sub 2})/H{sub 2}O and 1,3-dimethylurea-d{sub 2}(DMUd{sub 2})/D{sub 2}O solutions (1, 2, 4, 12, and 20 m{sub aq}, 15 < t/{degree}C < 80) were obtained from differential vapor pressure measurements. Excess partial molar free energies, enthalpies, and entropies for the solvent and their isotope effects were calculated from the temperature derivatives of the osmotic coefficients. New partial molar volume data are reported at 25 C at low and intermediate concentrations. The thermodynamic properties of solution are compared with those of urea and discussed using the cage model of hydrophobic hydration. The results support the mixed (polar-apolar) character of this compound and show that its structural effect on water changes with temperature and concentration.
- Sponsoring Organization:
- National Insts. of Health, Bethesda, MD (United States); USDOE, Washington, DC (United States)
- OSTI ID:
- 562323
- Journal Information:
- Journal of Chemical and Engineering Data, Vol. 42, Issue 6; Other Information: PBD: Nov-Dec 1997
- Country of Publication:
- United States
- Language:
- English
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