There are only a few reported measurements dealing with the solubility of 1,4-dibromobenzene in water. In the published papers on the subject, the determination of solubility is not the primary purpose of the work, a fact that may affect the precision of the reported results. Of the values reported, only that of Andrews and Keefer (1) refers to 298.2 K. The measured data reported by Hine, Haworth, and Ramsay (2) St 308.2 K lend some support to the value assigned at 298.2 K.
The experimental procedure employed by Andrews and Keefer is adequate for the determination in question. However, the time of equilibrium (about 20 hours as given in (3)) seems quite short in the absence of tests for solution equilibrium. It is reasonable to attribute most of the uncertainty in the reported solubility of 8.5 x 10-5 mol(l)/dm3 (7.0 x 10-5 molar at an ionic strength of 1.0 molar, a figure incorrectly cited for solubility in pure water in some papers). Support for the reliability of the value at 298.2 K is provided by the value of 1.12 x 10-4 mol(l)/kg(2) given by Hine et al. for 308.2 K. This value was obtained by employing a long equilibration (at least a week) and a direct spectrophotometric measurement. In fact, it seems reasonable that the latter measurements should be more reliable than those of Andrews and Keefer although the agreement between the two measurements is quite satisfactory. The increase in the solubility is about 30% for a temperature rise of 10 degrees from 298.2 K. This increase is about the same magnitude as that for l,4-dichlorobenzene in water in the same range of temperature as measured by Wauchope and Getzen (4).
The following is the tentative solubility of 1,4-dibromobenzene in water at
298.15 K: