The 1,1,2,2-tetrachloroethane (1)
and water (2) binary system is treated in two parts; part 1 is 1,1,2,2-tetrachloroethane
(1) in water (2) and part 2 is water (2) in 1,1,2,2-tetrachloroethane (1).
Part 1. The solubility of 1,1,2,2-tetrachloroethane (1) in water (2) has been studied by 19 groups of workers in the temperature range from 276.15 to 419.35 K. Despite the large
number of investigations, the solubility values are very uncertain above 323.15 K.
Most of the solubility measurements
provide relatively consistent results with the exception of those by Hollo and
Lengyel1 and Prosyanov et al.2 These data appear
erratic when compared with other measurements. Furthermore, they appear inconsistent
in that they do not show comparable effects with increasing temperature and
are therefore rejected. The remaining solubility data of Wright and Schaffer,3
van Arkel and Vles,4 Othmer et al.,5 McGovern,6
Walraevens et al.,7 Chiou and Freed,8 Sato and
Nakijima,9 Schwarz,10 Veith et al.,11
Banerjee et al,12 Schwarz and Miller,13 Leighton
and Calo,14 McNally and Grob,15 Barr and Newsham,16
Howe et al.,17 Vogel,18 and Wright et al.19
were used to obtain the following mass percent (1) equation:
Solubility [100 w1] = 4.87975 – 3.0937 × 10–2
(T/K) + 5.20513 × 10–5 (T/K)2,
which shows a standard deviation of 4.54 × 10–2 in the temperature
range from 276.15 to 323.15 K.
The measurements and the curve obtained
from the smoothing equation are shown in Fig. 11. A solubility minimum appears
at 297.18 K. Additional details concerning the solubility minimum for aqueous
hydrocarbon systems are provided in the Preface.
The recommended solubility values
at 5 K intervals for 1,1,2,2-tetrachloroethane (1) in water (2) are presented
in Table 1.
Part 2. The solubility of
water (2) in 1,1,2,2-tetrachloroethane (1) has been studied by 11 groups of
workers, mostly at 298.15 K. The datum of Lees and Sarram20 is markedly
lower than other results and is therefore rejected. The measurements of Othmer
et al.,5 McGovern,6 and Zielinski21
are several per cent higher than the smoothed solubility values and are also
rejected. The solubilities calculated from the distribution coefficients of
Prosyanov et al.22 are in very poor agreement, giving no confidence
in the values which are regarded as dubious.
The remaining data of Staverman,23
Hutchison and Lyon,24 Johnson et al.,25
Johnson,26 Christian et al.,27 and Barr and Newsham16
were compiled or used for the smoothing equation. The fitting equation used
was:
log10 x2 = 1.3175 – 974.642/(T/K)
This equation represents the combined
data with a standard deviation of 3.36 × 10–2 in the 273-323 K temperature range.
The recommended solubilities at 5
K intervals for water in 1,1,2,2-tetrachloroethane are given in Table 2.
Measured values and the curve obtained
from the smoothing equation for solubility expressed as log10 x 2
versus the reciprocal of absolute temperature are shown in Fig. 12.
It may be noted that all studies
show a general increase in solubility with temperature which is consistent with
the theory of water solubility for halogenated hydrocarbons as discussed in
the Preface. As a common practice, the temperature dependence of solubility
is often plotted on a Cox chart, that is, log10 x 2
versus 1/(T/K), in which case a straight line usually represents the
data, at least over some limited temperature range.