ISSN:
1572-8927
Keywords:
Mutual diffusion
;
ternary solutions
;
densities
;
ZnCl2
;
KCl
;
transport properties
;
aqueous solutions
Source:
Springer Online Journal Archives 1860-2000
Topics:
Chemistry and Pharmacology
Notes:
Abstract Mutual diffusion coefficients and densities were measured for aqueous ZnCl2−KCl mixtures at 25° by using free-diffusion Rayleigh interferometry and pycnometry, respectively. The ZnCl2 concentrations were fixed at 1.5 mol-dm−3, whereas those of KCl were 0.5, 1.25, 2.0, or 4.0 mol-dm−3. This corresponds to a half charged zinc-chlorine storage battery at various suporting electrolyte concentrations. The main-term coefficient of ZnCl2 only varies by 10% with KCl concentration, whereas that of KCl varies by about 22%. The ZnCl2 cross-term coefficient remains small and positive; in contrast the KCl cross-term coefficient goes through a maximum and is negative at high and low KCl concentrations. At KCl concentrations of 0.5 and 4.0 mol-dm−3, solutions with the KCl Δc≈0 are statically and dynamically (diffusively) unstable at the top and bottom of the boundary. Evaluation of the parameters of the non-linear least-squares solution to the diffusion equation is difficult for the 1.25 mol-dm−3 KCl case, since this system has nearly equal eigenvalues in its diffusion coefficient matrix.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00646608
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