Stability Constants of NaCO3-, NaSO4- and KCO3- in Water at 25°C

Author

Frank Dennis Blum, Eastern Illinois University

Degree Name

Master of Science (MS)

Semester of Degree Completion

1977

Thesis Director

David W. Ebdon

Abstract

A new method for determining ion association constants in aqueous solutions using ion selective electrodes has been developed. This method has been applied to the NaCO₃^-, NaSO₄^- and KCO₃^- ion pairs at 25°C. Association constants for NaCO₃^- and NaSO₄^- were determined at various ionic strengths and extrapolated to zero ionic strength to yield 2.2 ± 0.2 for NaCO₃^- and 5.3 ± 0.4 for NaSO₄^-. Values for the association constants at an ionic strength near sea water (I=0.70) were calculated to be 1.7 ± 0.1 for NaCO₃^- and 2.1 ± 0.2 for NaSO₄^-. The KCO₃^- association constant was determined to be between zero and one.

Other less direct methods of determining these constants were tested and evaluated. It was also evident sodium m-benzenedisulfonate is a weakly associated electrolyte, which may associate to approximately the same extent as sodium carbonate. An Orion model 94-11 Sodium Ion Electrode, Orion model 93-19 Potassium Ion Electrode, Sensorex model S810C03 Carbonate Sensitive Electrode and Chemtrix model 1015M Sulfate Electrode were used and compared in this study.

Recommended Citation

Blum, Frank Dennis, "Stability Constants of NaCO3-, NaSO4- and KCO3- in Water at 25°C" (1977). Masters Theses. 3271.
https://thekeep.eiu.edu/theses/3271