Chemistry Reference
In-Depth Information
δ
x
11
δ
x
21
δ
x
31
0.06
0
0.01
3
1
0.04
0
-0.02
2
0.02
-0.01
-0.04
-0.02
0
-0.06
δ
x
32
δ
x
12
δ
x
22
0.06
0
0.02
0.01
0.04
-0.02
0
0.02
-0.04
-0.01
0
-0.02
-0.06
δ
x
23
δ
x
33
δ
x
13
0
0
0.01
-0.01
0
-0.01
FIGURE 4.6
Excess local compositions (
δ
x
ji
, Equation 4.30) for the ternary system trichlo-
romethane(1) + tetrahydrofuran(2) + cyclohexane(3) at 298.15 K. For all pictures, components
correspond to the three corners of the composition triangle as illustrated in the first panel.
values shown by the other systems have disappeared, all the Δ
G
ij
values being
small and of the same order of magnitude. The largest values are found for Δ
G
12
,
which are positive over the whole domain, while Δ
G
22
values are positive at cyH-
rich compositions and negative elsewhere; Δ
G
23
appears negative for all composi-
tions. These features indicate that it is the specific interaction by TCM and THF,
probably a CH-O bond, which prevails and is responsible for the behavior of all
Δ
G
ij
. Also, in this system Δ
G
33
is found to be positive for the whole domain, evi-
dently for the same reason. Being an inert compound, when the other components
undergo association driven by strong interactions, cyH is in a way compelled to
self-associate because of the repulsion exercised on it by the other two molecules,
as the negative Δ
G
13
and Δ
G
23
suggest. At compositions rich in cyH, some affinity
