The photochemistry of the nitrate radical and the kinetics of the nitrogen pentoxide-ozone system

摘要: The kinetics of the nitrogen pentoxide catalyzed decomposition ozone were studied in dark and with photolytic light absorbed by NO/sub 3/ radical. Ultraviolet, visible, or infrared absorption cross sections measured for N/sub 2/O/sub 5/, HNO/sub 3/, 2/ 3/. equilibrium constant 5/ reversible + was found to be (molecules cm/sup -3/, 298--329 K) K = (8.4 +- 1.8) x 10/sup 26/ exp(-(11180 100)/T). rate constants several reactions measured: (cm/sup molecule/sup -1/s/sup -1/) 2NO/sub ..-->.. O/sub 2/, g (8.5 2.8) -13/ exp(-(2450 100)/T); O product, m less than equal 2 -14/; n (1.0 0.4) -11/. By combining literature values Ke Kf, e f evaluated: NO (2.5 0.5) -14/ exp(-(1230 =more » (1.9 -11/ at 297 K. At 1 atm total pressure, photolysis occurs a primary quantum yield one red region spectrum. solar 298 two paths dissociation are consistent following values: h..nu.. j/sub 1/ 0.040 0.02 s/sup -1/; O, 0.099 -1/. average process approximately 0.77 wavelengths between 470 610 nm, that about 0.23 nm but only 0.07 strong 670 nm. may larger lower pressures. Infrared ascribed is due 5/; previously reported visible factor 4 too low corrected here; ultraviolet reversed slightly.« less