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Title: Ternary mutual diffusion coefficients of NaCl-SrCl/sub 2/-H/sub 2/O at 25/degrees/C. 2. Total concentrations of 2. 0 and 3. 0 mol/times/dm/sup /minus/3/

Journal Article · · J. Phys. Chem.; (United States)
DOI:https://doi.org/10.1021/j100332a056· OSTI ID:5994218

Mutual diffusion coefficients were measured for aqueous NaCl-SrCl/sub 2/ mixtures at 25/degrees/C by using free-diffusion Rayleigh interferometry. These mixtures were total molarities of 2.0 and 3.0 mol/times/dm/sup /minus/3/ with molarity fractions of 2/3, 1/2, and 1/3, the results complement the authors earlier data at 0.5 and 1.0 mol/times/dm/sup /minus/3/. At a constant molarity ratio, the NaCl main-term coefficient decreases regularly by 19-36% with increasing concentration, in contrast, the SrCl/sub 2/ main-term coefficient is relatively constant, with 18% or less variation with concentration. The SrCl/sub 2/ cross-term coefficient is 7-23% of its corresponding main-term coefficient, whereas the NaCl cross-term coefficient varies from 8% to 73% of its corresponding main-term coefficient. Clearly, coupled diffusion is very important for these systems. Various estimation procedures were considered, including variations using the Nernst-Hartley equations and estimates from the corresponding binary solutions. None of these methods, for which sufficient auxiliary data are available, gave reliable estimates of diffusion coefficients for mixtures. At a total molarity of 3.0 mol/times/dm/sup /minus/3/ and molarity fractions of 1/2 and 1/3 NaCl, experiments with the SrCl/sub 2/ ..delta..c approx. 0 are convectively unstable with regard to fingering at the center of the boundary. Density data were also measured for the above systems.

Research Organization:
Lawrence Livermore Lab., CA (USA)
DOE Contract Number:
W-7405-ENG-48
OSTI ID:
5994218
Journal Information:
J. Phys. Chem.; (United States), Vol. 92:21
Country of Publication:
United States
Language:
English