Aqueous aerosol oxidation of nitrous acid by O2, O3 AND H2O2

We have measured the rate of oxidation of nitrous acid to nitric acid by O2, O3 and H2O2 in aqueous solution in the pH range 0-4. The rate expressions at 25 Celsius are: (moles ℓ−1 s−1) −d(O2)/dt = 36(HNO2)2(O2) (±50%)−d(O3)/dt = 5.0 × 105(O3)(NO2−)(±20%)−d(NIII)/dt = 4.6 × 103(H +)(H2O2)(HNO2) (±20%). An atmospheric calculation is given to show that the O3 oxidation could be a significant sink for HNO2 in clouds at pH approximately 4.5 and higher, and the H2O2 reaction could be a significant sink at pH approximately 2.0 and lower.