UPTAKE OF NO3 ON WATER SOLUTIONS - RATE COEFFICIENTS FOR REACTIONS OFNO3 WITH CLOUD-WATER CONSTITUENTS

The reactive uptake coefficients, gamma, of NO3 onto aqueous solutions containing ions X(-) = HSO3-, SO32-, HCOO-, CH3COO-, and OH- were mea sured at 273 +/- 1 K using a wetted-wall flow tube reactor. The values of (HD)-D-2/k (H = Henry's law coefficient, D-/ = diffusion coefficie nt in the liquid phase, and k = second-order rate coefficient for the liquid phase reactions of NO3 with X(-)) for the reactive uptake of NO 3 were determined by measuring gamma as a function of liquid phase rea ctant concentration. The linear correlation between the measured rate coefficients and those for corresponding SO4- reactions, and the depen dence of the measured rate coefficients on the redox potential of the X/X(-) pair suggest that the NO3 + X(-) reactions proceed by electron transfer. The atmospheric implications of these findings are briefly d iscussed.