THE PRESSURE-DEPENDENCE OF THE THERMAL-DECOMPOSITION OF N2O

The pressure dependence of the thermal decomposition of nitrous oxide was investigated behind shock waves at temperatures between 1570 K and 5100 K and pressures from 0.3 atm to 450 atm. Nitrous oxide concentra tion profiles were measured using IR emission from the 4.5 mu m v(1) b and of N2O. 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(lo) = 10(14.6+/-0.6)e xp(-(237+/-5) kJ mol(-1)/RT) cm(3) mol(-1) s(-1) k(l infinity) = 10(12 .1+/-0.4)exp(-(262+/-3) kJ mol(-1)/RT) s(-1) These values were used to extrapolate current measurements of the rate coefficient to lower tem peratures, where the agreement with past work is excellent. Therefore the limiting rate coefficients given above should be suitable for kine tic modeling over a temperature range of 800-2000 K and pressures up t o 450 atm. (C) 1996 John Wiley & Sons, Inc.