Thermodynamic properties of aqueous solutions of the alkali metal chlorides to 250/sup 0/C

Journal Article · Thu Mar 31 04:00:00 EST 1983 · J. Phys. Chem.; (United States)

DOI:https://doi.org/10.1021/j100230a030· OSTI ID:5522017

Holmes, H F; Mesmer, R E

Osmotic coefficients of LiCl(aq), KCl(aq), and CsCl(aq) have been determined, at 225 and 250/sup 0/C, by isopiestic comparison with NaCl(aq). Equilibrium molalities ranged up to 8 mol kg/sup -1/. Isothermal osmotic data can be precisely described by the ion interaction model of Pitzer. The osmotic, and activity, coefficients continue to decrease with increasing temperature with LiCl(aq) retaining a measure of individuality when compared to the other alkali metal chlorides. Our present results have been compared and combined with previously reported thermodynamic data (isopiestic and vapor pressure measurements, electrochemical cell potentials, freezing temperature determinations, enthalpies of solution and dilution, and heat capacities) within the framework of the ion interaction model. The resulting set of equations provides a thermodynamic description, essentially within the accuracy of the reported experimental results, of LiCl(aq), KCl(aq), and CsCl(aq) as a function of temperature (from 0 to 250 /sup 0/C) and molality (up to about 6 mol kg/sup -1/). The ion interaction parameter ..beta../sup (0)/ was in the order LiCl > NaCl > KCl > CsCl at all temperatures. The same trend was observed for the excess thermodynamic properties phi, ..gamma.., and /sup phi/L. Contributions of the short-range interactions to the activity coefficient (ln ..gamma.. - f/sup ..gamma../) are shown to be linearly related to the reciprocal radius of the cation. Excess free energy data for the alkali metal chlorides to 250/sup 0/C can be modeled surprisingly well with a single parameter--the hard-core diameter--using the theoretical form of the ion interaction model.

• Research Organization: Oak Ridge National Laboratory, TN
• DOE Contract Number: W-7405-ENG-26
• OSTI ID: 5522017
• Journal Information: J. Phys. Chem.; (United States), Journal Name: J. Phys. Chem.; (United States) Vol. 87:7; ISSN JPCHA
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
400201* -- Chemical & Physicochemical Properties
ALKALI METAL COMPOUNDS
AQUEOUS SOLUTIONS
CATIONS
CESIUM CHLORIDES
CESIUM COMPOUNDS
CHARGED PARTICLES
CHLORIDES
CHLORINE COMPOUNDS
DIFFUSION
DISPERSIONS
ENERGY
EQUILIBRIUM
FREE ENERGY
HALIDES
HALOGEN COMPOUNDS
HIGH TEMPERATURE
IONS
ISOTHERMAL PROCESSES
LITHIUM CHLORIDES
LITHIUM COMPOUNDS
LITHIUM HALIDES
MEDIUM TEMPERATURE
MIXTURES
OSMOSIS
PHYSICAL PROPERTIES
POTASSIUM CHLORIDES
POTASSIUM COMPOUNDS
SODIUM CHLORIDES
SODIUM COMPOUNDS
SOLUTIONS
TEMPERATURE DEPENDENCE
THERMODYNAMIC PROPERTIES