Limiting activity coefficients of some aromatic and aliphatic nitro compounds in water

Limiting activity coefficients of nine nitroaromatic compounds and four nit roalkanes in water were determined in the range of environmentally related temperatures by measuring suitable phase equilibria. For liquid and solid n itroaromatics (nitrobenzene, 2-nitrotoluene, 3-nitrotoluene, 4-nitrotoluene , 2-nitrophenol, 3-nitrophenol, 4-nitrophenol, 1-chloro-2-nitrobenzene, and 1-chloro-4-nitrobenzene) the aqueous solubilities were measured by a conve ntional batch contacting method with UV spectrophotometric analysis, while for nitroalkanes (nitromethane, nitroethane, 1-nitropropane, and 2-nitropro pane) the air-water partitioning (Henry's law constant H-12 or air-water pa rtition coefficient K-aw) was determined by the inert gas stripping method employing gas chromatography. Whenever possible, our results were compared to literature values. Calculation of H-12 or K-aw for nitroaromatics from t he measured solubilities is hindered by the lack of reliable vapor pressure data. On the basis of the temperature dependences of the solubilities meas ured, the enthalpies of solution at infinite dilution for the nitroaromatic s in water were evaluated.