ISSN:
1572-8927
Keywords:
Enthalpy of dilution
;
electrolyte solutions
;
Debye-Hückel theory
;
limiting Debye slope
;
sodium chloride solutions
;
partial molar enthalpies
;
apparent molar enthalpies
Source:
Springer Online Journal Archives 1860-2000
Topics:
Chemistry and Pharmacology
Notes:
Abstract Analysis of enthalpy of dilution data for the system NaCl/H2O at 298.15°K with correlating equations presently in widespread use shows that these do not satisfactorily fit the data at the lowest available concentrations. A new approach based on the extended Debye-Hückel theory is suggested. It is shown that a plot of the ratio of the apparent molar enthalpy of dilution to the change in ionic strength, ΔϕL/ΔI, versus (I i 1/2 −I f 1/2 )/ΔI, should give a straight line at low enough concentration with a slope 2S H/3. The intercept is related to the Debye distance parameterA′ and the coefficient of the first virial correction term. The quantityS H is the limiting Debye slope as calculated from the properties of the pure solvent. These expectations are substantiated by the fits. Values of the parameters are compared with older estimates, and it is concluded that the choiceA′=0 is reasonable.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00644481
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