The Thermal Decomposition of Nitromethane

Abstract

A study of the thermal decomposition of nitromethane was made by the flow method, with nitrogen as carrier gas, the reaction being followed by polarographic analysis of the effluent from the furnace for nitromethane. When carefully dried nitrogen was used the rate of disappearance of nitromethane became erratic; it was, however, found possible to obtain reproducible results by passing wet nitrogen through the unit before the kinetic run. The decomposition follows the first‐order law, and over the range 420–480°C is represented by the equation k=2.7×10¹³ exp(−50 000/RT) sec⁻¹. At 420°, k is in good agreement with the value obtained by Cottrell, Graham, and Reid by the static method, but at higher temperatures the observed rate is lower than that computed from their equation. Although the energy of activation is close to that required to break the C–N bond, the high initial yield of formaldehyde obtained in the flow‐method experiments suggests that the rate is in part determined by an intramolecular rearrangement.