Abstract
Equations previously developed and widely applied to the thermodynamic properties of strong electrolytes are extended to solutions involving a dissociation equilibrium. Excellent agreement is obtained with the data for pure phosphoric acid to 6M and for phosphate buffer solutions. The parameters of the strong electrolyte components of the buffer solutions are taken from other work, and the remaining parameters for H+, H2PO −4 , and H3PO4 are evaluated, including a pK of 2.146. The present method avoids ambiguities which formerly arose in treating weak acids with as small pK as this.
This is a preview of subscription content, log in via an institution to check access.
Similar content being viewed by others
References
K. S. Pitzer,J. Phys. Chem. 77, 268 (1973).
K. S. Pitzer and G. Mayorga,J. Phys. Chem. 77, 2300 (1973).
K. S. Pitzer and G. Mayorga,J. Solution Chem. 3, 539 (1974).
K. S. Pitzer and J. J. Kim,J. Am. Chem. Soc. 96, 5701 (1974).
R. G. Bates,J. Res. Nat. Bur. Stand. 47, 127 (1951).
W. J. Hamer,The Structure of Electrolyte Solutions (John Wiley & Sons, New York, 1959), Chap. 15.
K. S. Pitzer and L. Brewer, inThermodynamics, G. N. Lewis and M. Randall, eds. (McGraw-Hill, New York, 1961), pp. 587–590.
T. H. Lilley and C. C. Briggs,Electrochim. Acta 20, 253 (1975).
T. L. Hill,Introduction to Statistical Mechanics (Addison-Wesley, Reading, Mass., 1960), Chap. 19.
K. L. Elmore, C. M. Mason, and J. H. Christensen,J. Am. Chem. Soc. 68, 2528 (1946).
R. F. Platford,J. Solution Chem. 4, 591 (1975).
C. W. Childs, C. J. Downes, and R. F. Platford,Aust. J. Chem. 26, 863 (1973).
C. W. Childs, C. J. Downes, and R. F. Platford,J. Solution Chem. 3, 139 (1974).
K. L. Elmore, J. D. Hatfield, R. L. Dunn, and A. D. Jones,J. Phys. Chem. 69, 3520 (1965).
M. Selvaratnam and M. Spiro,Trans. Faraday Soc. 61, 360 (1965).
C. W. Childs,J. Phys. Chem. 73, 2956 (1969);Inorg. Chem. 9, 2465 (1970).
A. A. Ivakin and E. M. Voronova,Russ. J. Inorg. Chem. 18, 465 (1973).
R. H. Wood and R. F. Platford,J. Solution Chem. 4, 977 (1975).
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Pitzer, K.S., Silvester, L.F. Thermodynamics of electrolytes. VI. Weak electrolytes including H3PO4 . J Solution Chem 5, 269–278 (1976). https://doi.org/10.1007/BF00645465
Received:
Issue Date:
DOI: https://doi.org/10.1007/BF00645465