Salt effects in alcohol-water solutions. Application of scaled particle theory to the salting-out of polar molecules

1971 ◽  
Vol 75 (24) ◽  
pp. 3757-3764 ◽  
Author(s):  
Floyd L. Wilcox ◽  
Eugene E. Schrier
1990 ◽  
Vol 86 (6) ◽  
pp. 931-936 ◽  
Author(s):  
Anna-Kaisa Kontturi ◽  
Kyösti Kontturi ◽  
Lasse Murtomäki ◽  
David J. Schiffrin

1976 ◽  
Vol 54 (23) ◽  
pp. 3800-3808 ◽  
Author(s):  
Nicole Desrosiers ◽  
Jacques E. Desnoyers

The enthalpies, heat capacities, and volumes of transfer of the tetrabutylammonium ion from water to urea–water, tert-butyl alcohol–water, and sodium chloride–water mixtures have been calculated at 25 °C using the scaled-particle theory. In general, the signs, magnitudes, and overall trends in the cosolvent concentration dependence of the properties are predicted from the cavity contributions only. These calculations are found to be very sensitive to the diameters chosen for the various species.For these calculations it was necessary to measure with a dilatometer the coefficients of thermal expansion of tert-butyl alcohol–water mixtures as a function of concentration and temperature.


1982 ◽  
Vol 60 (11) ◽  
pp. 1317-1326 ◽  
Author(s):  
Robert Aveyard

A simple approach is developed for the salting-out of nonpolar molecules by strongly solvated salts. The standard free energy of transfer of solute from pure solvent to salt solution, and hence the salting coefficient, k, is calculated in terms of the surface tension increment caused by the addition of salt to the solvent. In its simplest form the method gives k in terms of the molar volumes of solvent and solute, and the osmotic coefficient of the salt solution. It is more successful in the prediction of k than the McDevit and Long theory, and it also has advantages over the more complex scaled particle theory of salt effects. In addition to a range of nonpolar solutes, the salt effects on some alcohols are also considered but application to polar solutes generally requires a knowledge of experimentally determined surface tension increments which are not widely available. The correct order of magnitude for the temperature coefficient of k at room temperature for some alkanes and H2 in water is given, although minima in k as a function of temperature, which have sometimes been observed, are not reproduced.


1984 ◽  
Vol 62 (1) ◽  
pp. 81-85 ◽  
Author(s):  
Norman H. Sagert ◽  
Danny W. P. Lau

The salting-out of triethylphosphate (TEP) from water was measured at 25 °C for twelve inorganic electrolytes. If salting out is taken as an additive property of ions, then the effectiveness for salting TEP out of water is [Formula: see text] for anions and [Formula: see text] for cations. The results were fitted to three theories. The distribution theory of Conway, Desnoyers, and Smith predicts the order of magnitude of the experimental results, but does not discriminate well between salts of the same valence type. The electrostriction theory of McDevit and Long discriminates well between ions but gives results three or five times larger than those observed. Scaled particle theory predicts the results reasonably well, but the predictions depend critically on the choice of ionic and molecular parameters. Thus, none of these theories is entirely satisfactory.


1979 ◽  
Vol 57 (1) ◽  
pp. 71-76 ◽  
Author(s):  
Michael H. Abraham ◽  
Asadollah Nasehzadeh

A novel method for the assessment of the Ph4As+/Ph4B− assumption for free energies of transfer of single ions has recently been suggested by Treiner, and used by him to deduce that the assumption is not valid for transfers between water, propylene carbonate, sulpholane, dimethylsulphoxide, N-methyl-2-pyrrolidone, and perhaps also dimethylformamide. The basis of the method is the estimation of the free energy of cavity formation by scaled-particle theory, together with the hypothesis that the free energy of interaction of Ph4As+ (or Ph4B−) with solvent molecules is the same in all solvents, ΔGt0(int) = 0. It is shown in the present paper that (a) whether or not the Ph4As+/Ph4B− assumption applies to transfer to a given solvent depends on which other solvent is taken as the reference solvent in Treiner's method, (b) the calculation of the cavity free energy term by scaled-particle theory and by the theory of Sinanoglu – Reisse – Moura Ramos (SRMR) yields values so different that the method cannot be considered reliable, (c) the calculation of cavity enthalpies and entropies for Ph4As+ or Ph4B− by scaled-particle theory yields results that are chemically not reasonable, (d) the hypothesis that ΔGt0(int) = 0 conflicts with SRMR theory, and (e) the conclusions reached by Treiner are not in accord with recent work that in general supports the Ph4As+/Ph4B− assumption for solvents that are rejected by Treiner.


1984 ◽  
Vol 19 (5) ◽  
pp. 544-548 ◽  
Author(s):  
S. Ya. Kuchmii ◽  
A. V. Korzhak ◽  
A. I. Kryukov

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