RESUMO
The surface tensions of aqueous salt solutions of LiCl, KCl, and CsCl were measured as a function of concentration and temperature. By analyzing the results, the thermodynamic quantities of surface formation such as entropy (Deltas), Helmholtz free energy (Deltaf), and energy of surface formation (Deltau) were evaluated. Addition of salts into aqueous solution leads to an increase in Deltaf but decreases in Deltas and Deltau. The variations of Deltas, Deltaf, and Deltau with the change of salt concentration are almost the same for all alkali metal chlorides in spite of their large difference in hydration force. Copyright 1999 Academic Press.
RESUMO
The surface tensions of aqueous solutions of sodium, magnesium, and lanthanum chlorides were measured as a function of concentration and temperature. By analyzing the results, the concentration dependence of the thermodynamic quantities of surface formation such as entropy (Deltas), Helmholtz free energy (Deltaf), and energy of surface formation (Deltau) were evaluated. The Deltaf increased almost linearly with increasing concentration, and the degree of the increase is mainly determined by the net charges of the salts. The Deltas decreased with the addition of salt into the solution. It was found that the net charge of salts determines the degree of the decrease in Deltas. On the other hand, a slight change in the Deltau is observed because of the opposite contribution of Deltaf and TDeltas to the Deltau value. Copyright 1999 Academic Press.
RESUMO
The surface tensions of binary salt mixtures made up from NaCl and MgCl2 in aqueous solution were measured as a function of concentration and temperature. By analyzing the results, the thermodynamic quantities of surface formation such as entropy (Deltas), Helmholtz free energy (Deltaf), and energy of surface formation (Deltau) were evaluated. The Deltaf of the mixtures positively deviates from the straight line connecting those of NaCl and MgCl2 aqueous solutions. On the other hand, Deltas shows negative deviation from the linear relation. Copyright 1999 Academic Press.
