Pitzer equations

Pitzer equations[1] are important for the understanding of the behaviour of ions dissolved in natural waters such as rivers, lakes and sea-water.[2][3][4] They were first described by physical chemist Kenneth Pitzer.[5] The parameters of the Pitzer equations are linear combinations of parameters, of a virial expansion of the excess Gibbs free energy, which characterise interactions amongst ions and solvent. The derivation is thermodynamically rigorous at a given level of expansion. The parameters may be derived from various experimental data such as the osmotic coefficient, mixed ion activity coefficients, and salt solubility. They can be used to calculate mixed ion activity coefficients and water activities in solutions of high ionic strength for which the Debye–Hückel theory is no longer adequate. They are more rigorous than the equations of specific ion interaction theory (SIT theory), but Pitzer parameters are more difficult to determine experimentally than SIT parameters.

  1. ^ Pitzer, Kenneth S. (1991). Activity coefficients in electrolyte solutions (2nd ed.). Boca Raton: CRC Press. ISBN 0849354153.
  2. ^ Stumm, W.; Morgan, J.J. (1996). Water Chemistry. New York: Wiley. ISBN 0-471-05196-9.
  3. ^ Snoeyink, V.L.; Jenkins, D. (1980). Aquatic Chemistry: Chemical Equilibria and Rates in Natural Waters. New York: Wiley. ISBN 0-471-51185-4.
  4. ^ Millero, F.J. (2006). Chemical Oceanography (3rd ed.). London: Taylor and Francis. ISBN 0-8493-2280-4.
  5. ^ E. Connick, Robert E. Connick (December 2000). "Kenneth Pitzer, 6 January 1914 · 26 December 1997". Proceedings of the American Philosophical Society. 14 (4): 479–483. JSTOR 1515624.