Ternary solution mutual diffusion coefficients and densities of aqueous mixtures of NaCl and Na{sub 2}SO{sub 4} at 298.15 K for six different solute fractions at a total molarity of 1.000 mol/dm{sup 3}
- Texas Christian Univ., Fort Worth, TX (United States). Chemistry Dept.
- Lawrence Livermore National Lab., CA (United States)
Isothermal mutual diffusion coefficients (interdiffusion coefficients) were measured for ternary aqueous mixtures of NaCl and Na{sub 2}SO{sub 4} at a constant total molarity of 1.000 mol/dm{sup 3} and 298.15 K. Measurements were performed using Rayleigh interferometry with computerized data acquisition at NaCl molarity fractions of z{sub 1} = 1, 0.90, 0.75, 0.50, 0.25, and 0. Densities of the solutions were measured with a vibrating tube densimeter. At all ternary solution compositions, one cross-term diffusion coefficient has negative values whereas the other has positive values. These measurements supplement earlier results at 0.500 mol/dm{sup 3}. Both main-term diffusion coefficients are significantly smaller at 1.000 mol/dm{sup 3} than at 0.500 mol/dm{sup 3} at any fixed value of z{sub 1}, whereas both cross-term coefficients are shifted in a positive direction. Trace diffusion coefficients D{sup *}(Cl{sup {minus}}) and D{sup *}(SO{sub 4}{sup 2{minus}}) were extrapolated from these results for the Cl{sup {minus}}(aq) ion in 1.0 mol/dm{sup 3} Na{sub 2}SO{sub 4}(aq) and for the SO{sub 4}{sup 2{minus}} (aq) ion in 1.0 mol/dm{sup 3} NaCl(aq). Values of D{sup *}(Cl{sup {minus}}) in Na{sub 2}SO{sub 4}(aq) and in NaCl(aq) were found to be essentially identical, as were D{sup *}(SO{sub 4}{sup 2{minus}}) in these same two electrolytes, provided the comparisons were made at the same volumetric ionic strengths.
- Sponsoring Organization:
- National Aeronautics and Space Administration, Washington, DC (United States); USDOE, Washington, DC (United States)
- DOE Contract Number:
- W-7405-ENG-48
- OSTI ID:
- 653515
- Journal Information:
- Journal of Chemical and Engineering Data, Vol. 43, Issue 4; Other Information: PBD: Jul-Aug 1998
- Country of Publication:
- United States
- Language:
- English
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