Chemistry Reference
In-Depth Information
1.2
0.8
0.4
0
0
0.2
0.4
0.6
0.8
1
x
3
FIGURE 9.10
Calculated (lines) and experimental (symbols) excess solubilities,
x
Ex
, of
solid solutes in mixed solvents: Lower curve, anthracene(2)/n-octane(1)/1-butanol(3), ♦ Data
of J. M. Lepree, et al. (From J. M. Lepree, M. J. Mulski, and K. A. Connors, 1994, Solvent
Effects on Chemical Processes. 6. The Phenomenological Model Applied to the Solubility
of Naphthalene and 4-Nitroaniline in Binary Aqueous-Organic Solvent Mixtures,
Journal
of the Chemical Society-Perkin Transactions,
2, 1491.) Upper curve, β- carotene (2)/acetone
(1)/n- hexane (3),
▲
. (From A. Zvaigzne, I. Teng, E. Martinez, J. Trejo, and W. Acree, Jr., 1993,
Solubility of Anthracene in Binary Alkane + 1-Propanol and Alkane + 1-Butanol Solvent
Mixtures,
Journal of Chemical Engineering Data
, 38, 389.)
were assumed independent of temperature, though the obtained binary values did
vary with
T
.
In Ellegaard, Abildskov, and O'Connell (2010), data were analyzed from nine
pharmaceutical solutes in a total of 68 binary mixtures of 10 solvents, with some
of the mixtures at different temperatures. The absolute average relative deviation of
using parameters from binary data was 23% while that from correlation of ternary
data was 11%. Additional study of this method is described in Ellegaard (2011) with
more solutes and binary solvents, as well as in some ternary solvents. Figure 9.10
shows excess solubility results for representative systems.
9.4 FLUCTUATION SOLUTION THEORY PROPERTIES OF REACTIVE
COMPONENTS AND STRONG ELECTROLYTE SOLUTIONS
The FST statistical mechanics described above are for nonelectrolyte systems. The
treatment of solutions of ionizing salts, or in fact any system where speciation of
the input components occurs, requires additional analysis. This section describes
some elements of this area; other aspects are discussed in Chapter 8.
There are two general situations in which the particles in a solution do not have
the same identity as those that are put into the system: when a component dissociates
and when components can combine to form other species. The first case is com-
monly identified with salts forming ions with electrostatic charges. In both cases,
the reactions need not be complete, so that the solution can have the original spe-
cies (components) as well as the new species. Further, the speciation need not lead
to detectable entities. Thus, the “chemical theory of solutions” and the “solution of
