Thermodynamic Quantities of Surface Formation of Aqueous Electrolyte Solutions

Thermodynamic quantities of surface formation of aqueous electrolyte solutions VI. Comparison with typical nonelectrolytes, sucrose and glucose

“…This result is consistent with the idea that the ions are expelled from the surface and an ion-free layer is formed [2]. In the preceding papers of this series, experimental results on the effect of electrolytes necessary for understanding the behavior of ions in the surface region were reported [3][4][5][6][7]. One of the important results of this series is that the entropy of surface formation ( s) of aqueous solutions of alkali halides is smaller than that of pure water surface.…”

Thermodynamic quantities of surface formation of aqueous electrolyte solutions

“…For magnesium salts, however, it decreases in the order Cl − > NO − 3 > SO 2− 4 , in contrast to the decreasing order of surface potential SO 2− 4 > Cl − > NO − 3 . The magnitude of magnesium sulfate 1.67 mN m −1 mol kg −1 (25 • C) is nearly identical to that of 1:1 alkali metal chlorides and is almost half of that of magnesium chloride [14,15]. There is no adequate explanation by which this small value of magnesium sulfate may be predicted.…”

Thermodynamic quantities of surface formation of aqueous electrolyte solutions

“…Water was doubly distilled from dilute alkaline permanganate solution. Surface tension was measured by the drop volume method, which has proved useful through this series of measurements on electrolyte solutions [6][7][8][9][10][11]. Measurements were made using glass dropping tips.…”

“…In the preceding papers of this series, the experimental results on the effect of simple electrolytes necessary for the understanding of the behavior of ions in the surface region have been reported [6][7][8][9][10][11]. The reported surface tension data have confirmed that the effect of cations is primarily determined by the valence type, that the effect of anions and cations is clearly distinct in appearance, that the adsorption of electrolytes accompanies negative changes in the entropy of surface formation, and that the mixing of ions in the surface region provides peculiar curves of this entropy change.…”