Abstract
The stoichiometric pK1* and pK2* for the ionization of carbonic acid has been determined from emf measurements in NaCl soluions to 6.0m at 25°C. Our results at low concentrations are in good agreement with the results of Harned and Bonner, of Dyrssen and Hansson and of Roy et al. The calculated values of pK1* using Pitzer's equations agree with the measured values to ±0.01 pK units provided higher order terms are used. It was necessary to use a triplet interaction parameter (ψ) and higher order electrostatic terms (Eθ) to calculate reliable values of pK2* (±0.03 pK units) over the entire concentration range. These results demonstrate the reliability of the Pitzer equations to estimate activity coefficients in concentrated salt solutions.
Original language | English (US) |
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Pages (from-to) | 447-456 |
Number of pages | 10 |
Journal | Journal of Solution Chemistry |
Volume | 11 |
Issue number | 7 |
DOIs | |
State | Published - Jul 1 1982 |
Keywords
- Carbonic acid
- Pitzer's equations
- activity coefficients
- concentrated aqueous solutions
- ionization constants
ASJC Scopus subject areas
- Biophysics
- Biochemistry
- Molecular Biology
- Physical and Theoretical Chemistry