The Vapor Pressures and the Activity Coefficients of Aqueous Solutions of Perchloric Acid at 25°

The vapor pressures of aqueous solutions of perchloric acid have been measured at 25° for concentrations ranging from 0.1 m to 12.0 m. The activity of the water and the activity coefficients of the ions have been calculated and compared with those of hydrochloric acid for the same concentrations and at the same temperature. The free energy of transfer of both the solvent and the solute, and the partial molal volumes of both components have been calculated for each concentration. Deviations from Raoult\u27s law have been discussed in terms of the attraction of water dipoles by the electrically charged ions