Henry’s Constants of 2-Ketones in Aqueous Solutions Containing Inorganic or Quaternary Ammonium Salts

Henry’s constants of 2-propanone, 2-butanone, 2-pentanone, 2-hexanone, and 2-heptanone in aqueous solutions containing inorganic salts or quaternary ammonium salts were determined at temperatures between 313 and 343 K, and salt ionic strengths below 5.0. Our data show that inorganic salts generally salt-out the 2-ketones, whereas quaternary ammonium salts generally salt-in the 2-ketones. However, 2-propanone is salted-out by both types of salts. We have also extended a published model based on dilute solution theory to solutions containing two inorganic salts, as well as to solutions containing quaternary ammonium salts. We show that it is possible to correlate all data for salting-out behavior using a single salt-effect parameter for each system. Salting-in behavior can also be correlated with a single parameter, although agreement with experiment is not as good as in the case of salting-out behavior. This is because the model does not explicitly account for the role of dispersion forces in these systems, which may be inferred from the trends exhibited by the salt-effect parameter as the size of the 2-ketone increases in solutions containing quaternary ammonium salts.