Thermal Decomposition of Nitrocompounds in Shock Waves. IV: Decomposition of Nitric Acid

Abstract

AbstractThe thermal decomposition of nitric acid highly diluted in Ar has been studied in shock waves at 890 < T < 1200 K and 8.0 · 10−6 < [Ar] < 3.2 · 10−4mol cm−3. Concentration profiles of HNO3, NO2, and NO3 have been monitored. The rate constants of the unimolecular decomposition of HNO3 and the subsequent reaction OH + HNO3 can be determined directly. The results for the unimolecular decay and low temperature data of the combination reaction of HO and NO2 have been combined to derive expressions for the rate constants in the range between room temperature and 1200K. A reaction mechanism which accounts for the observed concentration profiles is discussed.