Keywords Aqueous systems bibliography biochemical systems enthalpy data entropy data equilibrium data excess properties Gibbs energy data heat capacHy data partial molar properties review articles thermochemistry thermodynamics. [Pg.739]

In aqueous systems, the enthalpy change due to micellization is usually positive, and micelliza-tion is driven by entropy change. Explain the reason for the positive entropy change. [Pg.398]

Criss, C.M. Cobble, J.W., "Thermodynamic Properties of High Temperature Aqueous Systems. IV Entropies of the Ions up to 200°C and the Correspondence Principles", JACS, 1964, 86, [Pg.246]

Millcro has also used the correspondence principle method to evaluate ionic volumes in NMP as well as in methanol. Similar to the case for entropies, ionic volumes in the non-aqueous system are plotted against the absolute 5n(aq) values, and the Vi (X) for the non-aqueous system assigned so that values for both cations and anions fall on the same line. The volumes can be expressed, similar to eqn. 2.11.36, as [Pg.287]

From here on we shall call the maximum-associated aqueous system maximum-structured, whereas the bound energy 6SAT can be spoken of as of structurization potential Ay.. The calculation of the value Ay from formula (506) shows that Aa RAT, where R is the gas constant. The calculation of the entropy from formula (508) yields the estimate 5 5 — R (the 5 versus T plot is presented in Fig. 32). [Pg.498]

Let us put S = S I 5.S and substitute this expression into Eq. (514). Then combining Eqs. (514) and (513), and taking Eq. (507) into account, we obtain the expression for estimating the entropy of a maximum-degassed disordered aqueous system [Pg.500]

In the linear approximation A5 = A5 in the same approximation at V const the change of internal energy can be estimated as AU = CyAT. Substituting expressions (502) and (507) with regard to explicit forms of 85 and AU into Eq. (506), we derive the expression for the entropy of the maximum-degassed associated aqueous system [Pg.498]

An analogous situation could also arise in the case of membrane separation of a concentrated mixture of CaCl2 and HCl, if the selectivity of the membrane would permit to clearly reject the Ca ions while easily transporting water, CP ions, and protons. Note that such spontaneous separation of two components must proceed with a decrease in entropy of the aqueous system. [Pg.474]

It might be expected that just below the UCFT, the enthalpies associated with the contact and free volume dissimilarities should impart enthalpic stabilization. Conversely, just above the LCFT (if accessible), the combinatorial entropy of mixing should give rise to entropic stabilization. Flocculation on cooling appears to result from the free volume contribution. This may explain why such flocculation is not always readily achieved in aqueous systems of this type. [Pg.159]

Estimations based on eqn. 2.11.36 or 2.12.10 assume that the constants a and b are known. When this is not the case, approximate estimates of a and b can probably be made, assuming that one can estimate the amount of structure in a solvent relative to those for which entropy data are already available. By interpolating between solvents one can then estimate the constant a from those listed in Table 2.11.13. With the exception of DMSO and DMF, the b constants in Table 2.11.13 for the non-aqueous systems are not too widely different, so it seems reasonable that an average of these values may give a fair estimate of b for other organic solvents. Fortunately, in eqn. 2.12.10 is not extremely [Pg.313]

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