The hydrolysis of CINO3 on sub micron liquid sulphuric acid aerosols

The reactive uptake of ClONO2 on liquid sulfuric acid has been measured for size‐selected, sub‐micron aerosol in the composition range 36–54% H2SO4 by weight at ≈ 250 K. A comparison with results from studies employing bulk surfaces at similar temperatures and compositions shows no evidence for a dependence of the reaction probability, γ, on size. We use this observation to estimate an upper limit to the diffuso‐reactive length of 26 nm for the ClONO2 + H2O reaction on 43 weight % aerosol at 248 K. But, the present values of γ are consistently lower than bulk values observed at lower temperatures and similar composition, suggesting that γ is temperature dependent.