Thermodynamic Properties of the NaCl + H2O System. 4. Heat Capacities of H2O and NaCl(aq) in Cold-Stable and Supercooled States

Published

September 1, 2000

Author(s)

Donald G. Archer, R W. Carter

Abstract

The heat capacities of water and NaCl(aq) from 0.05 to 6 mol.kg^-1 were measured from 285 K to a lower temperature of 202 K 2O system was generated on the bases of the present measurements as well as other experimental results that spanned the range of the solution to 100 Mpa. The present results for NaCl(aq) were examined in the context of the three competing interpretations of the anomalous properties of supercooled water. These are the stability limit conjecture, the critical point scenario, and the singularity-free interpretation. The present results lend support to the singularity-free interpretation. They also indicate that if a second critical point for water does exist at low temperature and high pressure, then the critical line for NaCl(aq) moves to lower temperatures with increasing concentration of NaCl. Solute activity coefficients from the equation of state for NaCl + H₂Owere also examined for evidence of ion association in the solution at supercooled temperatures.

Citation

Journal of Physical Chemistry B

Volume

104

Issue

No. 35

Pub Type

Journals

Keywords

aqueous, equation of state, heat capacities, sodium chloride, solutions, super-cooled, thermodynamics

Citation

Archer, D. and Carter, R. (2000), Thermodynamic Properties of the NaCl + H₂O System. 4. Heat Capacities of H₂O and NaCl(aq) in Cold-Stable and Supercooled States, Journal of Physical Chemistry B (Accessed October 2, 2023)