Mixtures of NH3 and N2O dilute in Ar were heated behind incident shock waves in the temperature range 1750–2060 K. A cw ring dye laser, tuned to the center of an OH absorption line in the ultraviolet, was used to monitor OH concentration profiles by absorption spectroscopy. Infrared emission was used to follow N2O (at 4.5 μm) and NH3 (at 10.5 μm) concentration—time histories. The early-time NH3 and OH concentration profiles were sensitive to the rate constants of the reactions leading to the following best-fit expressions for k2 and k3:k2 = 1013.34±0.3 exp(?4470/T) and k3 = 1013.91±0.2 exp(-4230/T) cm3 mol?1 s?1. The results of this study combined with previous low-temperature data suggest a significant non-Arrhenius behavior for both k2 and k3.
