We found a match
Your institution may have rights to this item. Sign in to continue.
- Title
Concentration, temperature, and isotopy effects on the heat capacity of aqueous urea.
- Authors
Korolev, V. P.
- Abstract
Relations for the apparent molar heat capacity ϕc of urea in an aqueous solution depending on the molality m and temperature were obtained. A transition to the relations ϕc( m, T) for D2O-(ND2)2CO and T2O-(NT2)2CO systems was effected by temperature scaling. At low temperatures, the isotherms of the molar heat capacity Cp( m) of the protium and deuterium systems have minima shifted to more dilute solutions at elevated temperatures. At m = 1, Cp of a solution does not depend on temperature in both systems. The dependences Cp( T) also have minima at constant concentrations. The temperature of the minimum heat capacity is most effectively lowered by small additions of urea. For m = 0.25, Tmin is 7.5 K lower than Tmin of pure water, and its heat capacity is 0.08 J/(mol K) higher. A transition from m = 1.5 to m = 2 lowers the temperature of the minimum heat capacity by 3.6 K; thus, the heat capacity of solutions differs by 0.02 J/(mol K) only.
- Subjects
TEMPERATURE; UREA; PROTIUM (Isotope); ATMOSPHERIC temperature; DEUTERIUM
- Publication
Journal of Structural Chemistry, 2009, Vol 50, Issue 6, p1096
- ISSN
0022-4766
- Publication type
Article
- DOI
10.1007/s10947-009-0161-5