FIGURE 7.14 Model-estimated increase in S(IV) oxidation in the aqueous phase of sea salt particles due to the uptake and reactions of NO,. 03 taken as 40 ppb, N02 as 0.1 ppb, and H202 as 0.05 ppb. The Y-axis is the calculated ratio of oxidized sulfur, S(VI), formed in droplets when NO, chemistry is included to that when it is not (adapted from Rudich et al., 1998).

with alkylbenzenes are also fast (k ~ 107—10s L mol~ 1 s-1) and likely proceed via electron transfer from the aromatic ring (Alfassi et al., 1993; Huie, 1995).

NO-, has also been observed to react with solid NaCl and KBr (Seisel et al., 1997). The reactions are believed to first generate atomic chlorine and bromine, respectively, i.e.,

N03(g) + NaCl(s) -» CI + NaNO,(s), (43) N03(g) + NaBr(s) ^ Br + NaN03(s). (44)

The products observed were HC1 and HBr + Br2, respectively (Seisel et al., 1997). These are likely due to the presence of small amounts of water on the salt surfaces (e.g., Beichert and Finlayson-Pitts, 1996). The reaction probabilities at room temperature were reported to be y43 = 4.9 X ltT2 and y44 = 0.16, respectively (Seisel et al., 1997).

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