Journal of Solution Chemistry

, Volume 4, Issue 3, pp 225–236 | Cite as

NaSO 4 ion pairs in aqueous solutions at pressures up to 2000 atm

  • F. H. Fisher
  • A. P. Fox


Electrical-conductance measurements have been made at 25° C up to concentrations of 0.06M in aqueous solutions of Na2SO4 at atmospheric pressure and as a function of pressure up to 2000 atm. Calculations of the change of the dissociation constant for the NaSO 4 ion pair with pressure indicate that the difference in partial molal volumes between products and reactants at infinite dilution is\(\Delta \bar V^ \circ \tilde = - 8.25{\text{ }}cm^3 /mole\). Using the equation of Davies, Otter, and Prue, we found the average dissociation constants for five concentrations between 0.005 and 0.06 moles/liter to be 0.097, 0.131, and 0.165 at 1, 1000, and 2000 atm, respectively, with a standard deviation of ±0.003. The atmospheric-pressure value is 0.080±0.016 over the entire concentration range from 0.00005 to 0.06 moles/liter, about half that obtained by Jenkins and Monk. This is consistent with a value ofK=0.077±0.006 recalculated from the limited-concentration-conductance work of Jenkins and Monk, with a value ofK=0.073 obtained by Fisher from data of Kurtze and Tamm on ultrasonic absorption in MgSO4−NaCl solutions, and withK=0.067 calculated by Fisher from the potentiometric data of Pytkowicz and Kester at high ionic strength. The relationship of this work to sound absorption and ion pairing in seawater is discussed. The predicted pressure dependence of the NaSO 4 ion pair in seawater from this work differs substantially from earlier work by Kester and Pytkowicz and by Millero.

Key words

NaSO4 ion pairing pressure electrical conductance 


Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.


  1. 1.
    D. R. Kester and R. M. Pytkowicz,Limnol. Oceanogr. 14, 686–692 (1969).Google Scholar
  2. 2.
    D. R. Kester and R. M. Pytkowicz,Geochim. Cosmochim. Acta 34, 1039–1051 (1970).Google Scholar
  3. 3.
    F. J. Millero,Geochim. Cosmochin. Acta 35, 1089–1098 (1971).Google Scholar
  4. 4.
    F. H. Fisher,Geochim. Cosmochim. Acta 36, 99–101 (1972).Google Scholar
  5. 5.
    F. H. Fisher,Science 157, 823 (1967).Google Scholar
  6. 6.
    F. H. Fisher,J. Phys. Chem. 66, 1607–1611 (1962).Google Scholar
  7. 7.
    R. A. Robinson and R. H. Stokes,Electrolyte Solutions, 2nd ed. (Butterworths, London, 1959), Chap. 14.Google Scholar
  8. 8.
    E. C. Righelatto and C. W. Davies,Trans. Faraday Soc. 26, 592–600 (1930).Google Scholar
  9. 9.
    C. W. Davies,Ion Association (Butterworths, Washington, 1962).Google Scholar
  10. 10.
    I. L. Jenkins and C. B. Monk,J. Am. Chem. Soc. 72, 2695–2698 (1950).Google Scholar
  11. 11.
    W. G. Davies, R. J. Otter, and J. E. Prue,Disc. Faraday Soc. 24, 103–107 (1957).Google Scholar
  12. 12.
    F. H. Fisher and D. F. Davis,J. Phys. Chem. 69, 2595–2598 (1965).Google Scholar
  13. 13.
    F. H. Fisher and D. F. Davis,J. Phys. Chem. 71, 819–822 (1967).Google Scholar
  14. 14.
    C. F. Hale and F. H. Spedding,J Phys. Chem. 76, 2925–2929 (1972).Google Scholar
  15. 15.
    B. B. Owen, R. C. Miller, and H. L. Cogan,J. Phys. Chem. 65, 2065–2070 (1961).Google Scholar
  16. 16.
    K. E. Bett and J. B. Cappi,Nature 207, 620–621 (1965); J. B. Cappi, Thesis, Imperial College, University of London, 1964.Google Scholar
  17. 17.
    G. S. Kell and E. Whalley,Phil. Trans. Roy. Soc. (London) A258, 565–617 (1965).Google Scholar
  18. 18.
    S. Lee, Ph.D. Thesis, Yale University, 1966.Google Scholar
  19. 19.
    M. Eigen and K. Tamm,Z. Elektrochem. 66, 93–121 (1962).Google Scholar
  20. 20.
    R. Zana and E. Yeager,J. Phys. Chem. 71, 521–536 (1967).Google Scholar
  21. 21.
    R. M. Pytkowicz and D. R. Kester,Am. J. Sci. 267, 217–229 (1969).Google Scholar
  22. 22.
    F. H. Fisher,J. Solution Chem. 4, 237–240 (1975).Google Scholar
  23. 23.
    S. Cabani and P. Gianni,Anal. Chem. 44, 253–259 (1972).Google Scholar

Copyright information

© Plenum Publishing Corporation 1975

Authors and Affiliations

  • F. H. Fisher
    • 1
  • A. P. Fox
    • 1
  1. 1.Marine Physical Laboratory of the Scripps Institution of OceanographyUniversity of California, San DiegoSan Diego

Personalised recommendations