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.
This is a preview of subscription content, log in via an institution to check access.
Similar content being viewed by others
References
Energy Development Associates, EPRI EM-1417, Electric Power Research Institute (Palo Alto, May 1980).
J.A. Rard and D.G. Miller,J. Phys. Chem. 91, 4614 (1987);92, 6133 (1988).
J.G. Albright, R. Mathew, D.G. Miller, and J.A. Rard,J. Phys. Chem. 93, 2176, (1989).
L. Paduano, R. Mathew, J.G. Albright, D.G. Miller, and J.A. Rard,J. Phys. Chem. 93, 4366 (1989).
R. Mathew, L. Paduano, J.G. Albright, D.G. Miller, and J.A. Rard,J. Phys. Chem. 93, 4370 (1989).
A. Agnew and R. Paterson,J. Chem. Soc. Faraday Trans. I. 74, 2896 (1978).
H. Weingärtner, K.J. Müller, H.G. Hertz, A.V.J. Edge, and R. Mills,J. Phys. Chem. 88, 2173, (1984).
J.A. Rard and D.G. Miller,Z. Phys. Chem. (Neue Folge) 142, 141 (1984).
D.G. Miller, A.W. Ting, and J.A. Rard,J. Electrochem. Soc. 135, 896 (1988).
D.G. Leaist,Ber. Bunsenges. Phys. Chem. 90, 797 (1986).
D.G. Miller, J.A. Rard, L.B. Eppstein, and J.G. Albright,J. Phys. Chem. 88, 5793 (1984): see the supplementary material for the alignment procedure.
J.A. Rard and D.G. Miller,J. Solution Chem. 8, 701 (1979).
J.A. Rard and D.G. Miller,J. Chem. Thermodyn. 21, 463 (1989).
P.J. Dunlop and L.J. Gosting,J. Phys. Chem. 63, 86 (1959).
J.A. Rard and D.G. Miller,J. Chem. Eng. Data 29, 151 (1984).
D.G. Miller,J. Phys. Chem. 71, 616 (1967).
D.G. Miller,J. Solution Chem. 10, 831 (1981).
D.G. Miller, A.W. Ting, J.A. Rard, and L.B. Eppstein,Geochim. Cosmochim. Acta 50, 2397 (1986).
H. Fujita and L.J. Gosting,J. Am. Chem. Soc. 78, 1099 (1956).
H.L. Toor,AIChE J. 10, 448, 460 (1956).
D. G. Miller, unpublished derivations.
D.G. Miller and V. Vitagliano,J. Phys. Chem. 90, 1706 (1986).
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Rard, J.A., Miller, D.G. Ternary mutual diffusion coefficients of ZnCl2−KCl−H2O at 25°C by Rayleigh interferometry. J Solution Chem 19, 129–148 (1990). https://doi.org/10.1007/BF00646608
Received:
Revised:
Issue Date:
DOI: https://doi.org/10.1007/BF00646608