Welcome to the new version of CaltechAUTHORS. Login is currently restricted to library staff. If you notice any issues, please email coda@library.caltech.edu
Published May 4, 2006 | public
Journal Article

Thermodynamic Models of Aqueous Solutions Containing Inorganic Electrolytes and Dicarboxylic Acids at 298.15 K. 2. Systems Including Dissociation Equilibria


Atmospheric aerosols contain a significant fraction of water-soluble organic compounds, including dicarboxylic acids. Pitzer activity coefficient models are developed, using a wide range of data at 298.15 K, for the following systems containing succinic acid (H_2Succ) and/or succinate salts: {H^+, Li^+, Na^+, K^+, Rb^+, Cs^+}Cl^-−H_2Succ−H_2O, HNO_3−H_2Succ−H_2O, H^+−NH_4^+−HSucc^-−Succ^(2-)−NH_3−H_2Succ−H_2O, NH_4Cl−(NH_4)_2Succ−H_2O, H^+−Na^+−HSucc^-−Succ^(2-)−Cl^-−H_2Succ−H_2O, NH_4NO_3−H_2Succ−H_2O, and H_2SO_4−H_2Succ−H_2O. The above compositions are given in terms of ions in the cases where acid dissociation was considered. Pitzer models were also developed for the following systems containing malonic acid (H_2Malo): H^+−Na^+−HMalo^-−Malo^(2-)−Cl^-−H_2Malo−H_2O, and H_2Malo−H_2SO_4−H_2O. The models are used to evaluate the extended Zdanovskii−Stokes−Robinson (ZSR) model proposed by Clegg and Seinfeld (J. Phys. Chem. A 2004, 108, 1008−1017) for calculating water and solute activities in solutions in which dissociation equilibria occur. The ZSR model yields satisfactory results only for systems that contain moderate to high concentrations of (nondissociating) supporting electrolyte. A practical modeling scheme is proposed for aqueous atmospheric aerosols containing both electrolytes and dissociating (organic) nonelectrolytes.

Additional Information

© 2006 American Chemical Society. Received 26 October 2005. Published online 4 April 2006. Published in print 1 May 2006. This work was supported by the U.S. Environmental Protection Agency, Grant RD-83107501 and Cooperative Agreement CR-831194001, and by the Natural Environment Research Council of the U.K. (as a part of the Tropospheric Organic Chemistry Experiment). The work has not been subject to the U.S. EPA's peer and policy review, and does not necessarily reflect the views of the Agency and no official endorsement should be inferred. The authors would like to thank those who made available their experimental data, and the Atmospheric Modeling Division of U.S. EPA for hosting Simon Clegg while carrying out this study. Note Added in Proof. Many of the data used in this work have been tabulated and are available at:  http:// www.uea.ac.uk/∼e770/aim.html.

Additional details

August 19, 2023
October 25, 2023