The pressure dependence of the thermal decomposition of N 2 O

The pressure dependence of the thermal decomposition of nitrous oxide was investigated behind shock waves at temperatures between 1570 K and 3100 K and pressures from 0.3 atm to 450 atm. Nitrous oxide concentration profiles were measured using IR emission from the 4.5‐μm ν 1 band of N 2 O. The pressure dependence of the measured rate constant was described using simple Lindemann fits, resulting in the following low‐ and high‐pressure limiting rate coefficients: $$k_{1^{_0}}=10^{14.6\pm 0.6}\exp(-(237\pm 5){\rm kJ\,mol^{-1}/RT}){\rm cm^3 mol^{-1}s^{-1}}$$ $$k_{1^{_\infty}}=10^{12.1\pm 0.4}\exp(-(262\pm 3) {\rm kJ\,mol^{-1}/RT}){\rm cm^3 mol^{-1}s^{-1}}$$ These values were used to extrapolate current measurements of the rate coefficient to lower temperatures, where the agreement with past work is excellent. Therefore the limiting rate coefficients given above should be suitable for kinetic modeling over a temperature range of 800–2000 K and pressures up to 450 atm. © 1996 John Wiley & Sons, Inc.