Experimentally determined Henry's Law coefficients of phenol, 2-methylphenol and 2-nitrophenol in the temperature range 281–302 K

Abstract

The Henry's Law coefficient is a key physical parameter in the partitioning, and hence environmental fate, of a chemical species between air and water. Despite the acknowledged polluting potential of phenol, 2-methylphenol ( o-cresol) and 2-nitrophenol, there is extremely poor agreement in the literature of their Henry's law coefficients and, in particular, no apparent systematic measurement of the variation with temperature. Here, a temperature-controlled column-stripping method was employed to determine Henry's Law coefficients for these compounds over the temperature range 281–302 K. Coefficients were derived from regression fits to the observed rates of losses from the liquid phase as a function of column depth in order to explicitly take account of potential non-attainment of equilibrium between liquid and gas phases. Temperature dependent expressions summarising the Henry's Law coefficients of phenol, o-cresol and 2-nitrophenol over the stated temperature range are ln H( M atm −1)=5850/T−11.6 , ln H( M atm −1)=6680/T−15.4 and ln H( M atm −1)=6270/T−16.6 , respectively (to within 15% of all measured values in this work). A thorough comparison with the previous literature-published values has been undertaken.