Surface Tension and Surface Thermodynamics of Aqueous Inorganic Salt Solutions in the Atmospherically Relevant Temperature Range

High Resolution Image Download MS PowerPoint Slide The surface tension γ of aqueous solutions of NaCl, NaBr, NaI, LiCl, KCl, MgCl 2, and Na 2 SO 4 (0.1 mol·kg –1 to 5 mol·kg –1 in maximum) was investigated within the atmospheric relevant temperature range of 263.15 to 293.15 K. The measured densities ρ of the aqueous inorganic salt solutions between 278.15 and 293.15 K are also reported. From experimental data the excess surface tension Δγ, the concentration (as molality m ) and temperature derivatives, (dγ/d m ) T, p and (dγ/d T ) p, m as well as thermodynamic quantities of surface formation such as surface excess entropy Δ s σ, surface excess Helmholtz energy Δ a σ, surface excess energy Δ u σ, and surface excess enthalpy Δ h σ were estimated. The surface excess entropy decreases slightly with increasing molality of the inorganic salt, which shows a weak order dependence of the water molecules on the salt concentration. The surface tension data and thermodynamic quantities complement existing data sets especially at temperatures below 283.15 K.