The rate of uptake of NO2 by liquid water according to (R1), 2NO2(g)+H2O(l)→2H+NO3-+NO2-, is shown to be unaffected by O2(0.2 atm). Hence the rate constant and Henry's law solubility constant of NO2 previously obtained may be employed to evaluate the rates of aqueous phase reactions of NO2 in the ambient atmosphere. Reactions (R1) and (R2), NO2(g)+NO(g)+H2O(l)→2H++2NO2-, are quite slow at representative atmospheric partial pressures and cloud liquid water content; the characteristic times range upward from 103--104 hours at 10-7 atm, increasing with decreasing partial pressures of the gases. Direct acidification of cloud liquid water by (R1) or (R2) is also unimportant. Catalytic enhancement of (R1) is potentially important for catalyst concentrations of order 10-7 M, assuming sufficiently fast rate constants (~108 M-1s-1). Iron-catalyzed reaction in particular, however, is found to be unimportant. Reaction of NO2 with dissolved S(IV) is potentially important, based upon an assumed upper limit rate constant of 2.5¿107 M-1 s-1. Deposition of NO2 to surface (ocean or lake) water is shown to be controlled by aqueous phase mass transport and/or reaction and is much slower than heretofore assumed.