Alkaline hydrolysis of trinitrotoluene, TNT
Abstract
The kinetics of the alkaline hydrolysis of OH− → Z) and B2 (Z + OH− → P). At 25 °C, Step B1 appears rate determining throughout the decay process. At 45 °C and, more so, at 60 °C, step B appears increasingly biphasic with increasing alkaline concentrations, as step B2 begins to compete with step B1 for position as the rate determining step. The trimolecular rate constant for step B1 is: 0.017 ± 0.001, 0.0085 ± 0.0002 and 0.0011 ± 0.0001 dm6 mol−2 s−1 at 25, 40 and 60 °C, respectively, and the process has an activation energy of 64 kJ mol−1. The transition from uniform kinetics, described by step B1, to mixed kinetics, described by steps B1 and B2, as the reaction temperature and alkali concentration are increased most likely occurs because (a) step B2 has a lower activation energy than B1, although it was not possible to measure the former parameter, and (b) step B2 has a lower (1st) order dependence upon [OH−] compared with that of step B1 (2nd). The bimolecular rate constant for step B2 is 0.0035 ± 0.03 dm3 mol−1 s−1 at 60 °C. A brief