The solubility of water in chlorobenzene baa been reported in eleven published works (5,9,12-20) in the temperature range between 288 and 322 K, see Figure 2.

Some of the more recent data for the solubility of chlorobenzene in water is that of Nelson and Smit (8) in the temperature range between 278 and 318 K. However, despite equilibrium periods of 24 hours (which might not have been long enough), the measured solubilities are substantially lower than those found by earlier investigators. It is not possible to establish any shortcomings of the experimental procedures from the very brief description. No information was provided on the source and purity of materials used. Also, it was not indicated whether or not a water stripper had been employed for the analysis of the very dilute aqueous solutions by gas chromatography, or whether or not an internal standard had been used for the calibration of the gas chromatograph which employed a flame ionization detector. However, the authors agreed to re-examine their raw data in order to verify the reported values (21). Consequently, for the present evaluation, their results have not been considered for inclusion in the selected solubility values.

The reported solubilities of Othmer et al. (9) and those of Newman et al (23) are too high in relation to the other reported solubility data. Consequently, these values have not been included in the correlation procedure. The approximate value given by Booth and Everson (3) has been excluded also from further consideration. The solubility data at high temperatures by Vorozhtsov and Kobelev (11) could not be correlated with the other data given. These remaining data given in (1,2,4-7,10,24,25) were correlated with Absolute temperature using polynomial equations of various degrees. The equation given below represents the solubility of chlorobenzene in water between 283 and 363 K within an estimated 10 percent. Equal weight was given to each of the data points in the regression procedure for the following equation:

Recommended solubility values between 283 and 363 K have been calculated from equation [1] and presented in Table 1. The solubility behavior described by equation [1] is shown also in Figure 1 which contains the reported experimental values for the solubility of chlorobenzene in water.

The solubility of water in chlorobenzene has also been investigated and reported by a number of workers (9,13,17,18,19,20,26) in the 298 to 318 K temperature range. In general, these solubility values show some irregularity, but those showing reasonable agreement can be correlated with respect to Absolute temperature. The reported solubilities of Zielinski (20) and of Othmer et al. (9) are too high while those of Jones and Monk (17) are too low. Consequently, these data are not considered further. Also, the solubility expressed as a distribution coefficient by an equation only (26) cannot be included in the correlation. The good agreement of the values at 298.15 K reported in (13,18,19) are heavily weighed in the correlation. The remaining data were all assigned equal weight to produce the following equation:

In this equation, x(2) is the mole fraction solubility of water in the chlorobenzene water system and T is the Absolute temperature. The calculated solubility values in the 273 to 333 K range are shown in Figure 2 along with the reported values.

The calculated mole fraction values for the solubility of water in chlorobenzene from equation [2] are given in Table 2 together with the corresponding molarities and g(2)/kg values in the temperature range between 283 and 333 K.

The azeotrope temperature (363.35 K) and composition (284 g(2)/kg) at 1.0133 x 10⁵ Pa pressure were also reported (22).

Experimental Data:   (Notes on the Nomenclature)