Part
2. The solubility of water (2) in trichloromomethane (1) has been studied by
25 workers as recorded in the Compilation Sheets immediately following this
Critical Evaluation. The reported solubilities in the 263 to 323 K temperature
interval are quite acceptable for using the smoothing equation as seen in Figure 2.
All the available data for the solubility of water (2) in trichloromomethane
(1) have been included for the fitting of the correlating equation with the
following exceptions. The measured data of Herz (ref. 1), Evans (ref. 17), De
Minjer (ref. 18), Reinders and De Minjer (ref. 19), and Kudryavtseva and Krutikova
(ref. 20) are rejected because they are significantly higher than later studies.
The data of Donahue and Bartell (ref. 21), Tettamanti et al. (ref. 22),
Christyakov and Shapurova (ref. 23), and Antropov et al. (ref. 24) are
markedly lower than other determinations and are therefore rejected.
The remaining data of 16 laboratories are in good agreement and the correlated
values above 253 K are recommended although the low temperature data (below
273 K) are probably dubious. Further studies are required to establish reliable
values in the lower temperature range below 273 K.
The equation for the mass per cent solubility of water (2) in trichloromomethane (1) between 263 and 323 K is as follows:
Solubility [100 w1] = 6.1195 × 10–2 – 2.0623 × 10–3 (T/K) + 7.20879 × 10–6 (T/K)2
This equation represents the combined data with a standard deviation of 2.2
× 10–2 and a correlation coefficient of 0.916.
The recommended solubility
values at 5 K intervals for water (2) in trichloromomethane (1) are presented
in the Table 2.
The curve obtained from the smoothing equation is shown in Figure 2. It may
be noted that all the studies show a general increase in the solubility with
temperature, which is consistent with the discussion of water solubility versus
temperature in the Preface. Often the temperature dependence of the solubility
is plotted on a Cox chart, that is, log10 x2 versus 1/T, where a straight line represents the solubility behavior. This procedure is very useful for the illustration of data covering a limited temperature range.
However, for the water (2) trichloromethane (2) system, this method of correlation was found to be less satisfactory than the regression with the normal polynomial equation.
Figure 3 shows the log10x2 versus the reciprocal of absolute temperature behavior for comparison with the behavior shown in Figure 2.
The trichloromethane (1) and water (2) binary system is discussed
in two parts; part 1 is trichloromethane (1) in water (2) and part 2 is water
(2) in trichloromethane (1).
Part 1. The solubility of trichloromomethane (1)
in water (2) has been studied by 54 workers with reasonable agreement of reported
values from a majority of the investigators.
The experimental data of most investigators in the 273 to 333 K temperature
interval are sufficiently reliable to use in the smoothing equation, see Figure 1. (The solid curve in the figure was obtained from the regression of all values
shown in the figure.) The experimental work of several workers was not used
for the smoothing equation for a variety of reasons. The solubility data of
Herz (ref. 1), Salkowski (ref. 2), Ababi et al. (ref. 3), Svetlanov et
al. (ref. 4), Sato and Nakijima (ref. 5), Veith et al. (ref. 6),
McNally and Grob (ref. 7), and Howe et al. (ref. 8) are markedly lower
than other results and are therefore rejected. The data of McCollum (ref. 9),
Booth and Everson (ref. 10), Aref'eva et al. (ref. 11), Coca et al.
(ref. 12), and Warner et al. (ref. 13) are several per cent higher than
the smoothed solubility values and are also rejected. Although, the measured
solubility data of Okuda (ref. 14) above 310 K are in reasonable agreement,
the low temperature data, that is, below 303 K are very uncertain. Consequently,
the low temperature data were not included in the regression analysis. Similar
inconsistency was found in the data of Hunter-Smith et al. (ref. 15)
and were excluded from further considerations. Lincoff and Gossett (ref. 16)
presented two methods for the determination of the solubility. The data determined
by the Batch Air Stripping method shows more compatible results and are in good
agreement, whereas it appears the EPICS method gave values too low. Therefore,
only the solubility data measured by the Batch Air Stripping method were used
for fitting the regression equation.
The combined data of 40 laboratories were correlated to obtain the following
mass per cent (1) equation:
Solubility [100 w1] = 12.5333 – 7.40557 × 10–2 (T/K) + 1.16374 × 10–4 (T/K)2
which shows a standard deviation of 5.6 × 10–2. This equation,
which shows a maximum deviation of 18 % (but much less for most of the data),
may be considered as representing the combined solubility values in the 273
to 333 K temperature range.
The solubility minimum (see Figure 1) calculated
from the regression equation is, in mass per cent (1), 0.752 at 318.18 K. The presence
of a minimum in the solubility versus temperature behavior for the halogenated
hydrocarbon-water systems is discussed in the Preface.
The recommended solubility values in mass per cent at 5 K intervals for trichloromomethane (1) in water (2) are presented
in Table 1.