Data for the solubility of 1,2-dichlorobenzene in water have been reported in several papers. The approximate solubility at 298.15 K was reported by Booth and Everson (1) while, somewhat earlier, Klemenc and Low (2) produced measurements between 293 and 333 K. More recent data have been published only between 276 and 307 K (8-11).
The approximate value provided by Booth and Everson is not given further consideration here. The remaining available data from (2, 8-11) have been correlated relative to absolute temperature using a normal polynomial equation:
S1(g(1)/kg) = 19.2314 - 1.81140 x 10-1 T
+ 5.6509 x 10-4T2 - 5.77683 x 10-7T3 [1]
The significance of this equation is that the curve representing the solubility data passes through a minimum at 283.7 K. This behavior is consistent with the theory discussed by Gill et al. (12) for the solubility of aromatic compounds in water.
Recommended solubility values between 273 and 333 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 1,2-dichlorohenzene in water.
The solubility of water in 1,2-dichiorobenzene has also been investigated and reported by a number of workers (3-7) in the 298 to 318 K temperature range. In general, these solubility values show some irregularity. While the agreement between the measurements of Jones and Honk (5) and those of Wing and Johnston (7) is reasonable, the deviation is considerable in relation to the measurements of Goldman (4) and of Kirchnerova and Cave (6) at 298.15 K. Identical measured values at 298.15 K were reported from the same department of McGill University by Goldman and by Kirchnerova and Cave.
From the description of the experimental measurements and the reliability if the results reported, it is not reasonable to exclude any of the data points except that quoted by Dreisbach (3) from further analysis. Therefore, all the water in 1,2-dichlorohenzene solubility data except that from Dreisbach were combined and incorporated in a regression equation. However, because of the long equilibration times allowed in Goldman and in Kirchnerova and Cave, their data points were given a weight twice as large as those values provided in Jones and Monk and in Wing and Johnston. The correlation equation is given by:
log10x(2) = 2.23134 - 1448.67/T [2]
In this equation, x(2) is the mole fraction solubility of water in the 1,2-dichiorobenzene-water system and T is the Absolute temperature. The calculated solubility values in the 273 and 333 K range are shown in Figure 2 along with the reported values.
The calculated mole fraction values for the solubility of water in 1,2-dichlorobenzene from equation [2] are given in Table 2 together with the corresponding molarities and g(2)/kg values in the temperature range between 293 and 328 K.