Vapor Pressures of Aqueous Solutions with Mixed Salts of NaCl + KBr and NaBr + KCl

摘要

The vapor pressures of aqueous NaCl + KBr and NaBr + KCl solutions were measured in the temperature range from 303.15 to 333.15 K and the electrolyte concentration range from 1 to 4 m. The experimental data showed that vapor pressures of these two aqueous mixed electrolyte solutions increase with increasing temperatures and almost linearly decreases with increasing concentrations of electrolyte. The experimental data also showed that, since these two aqueous mixed electrolyte solutions contian the same ions, an identical vapor pressure was observed at the same temperature and electrolyte concentration. This observation is consistent with the well understood fact that the particle interactions are identical in these solutions because the strong electrolytes are completely ionized in solution and have the same effect on the thermodynamic properties of water. The vapor pressures of these solutions were also estimated with the model of two-ionic-parameters for ion activity coefficient estimations proposed by Lin and Lee. The average absolute deviation (AAD) and the average absolute relative deviation (AARD) of NaCl + KBr aqueous solutions are 0.05 kPa and 0.41%, respectively, and those of NaBr + KCl aqueous solution are 0.05 kPa and 0.40%, respectively.