Enhancement of the air-water interfacial transfer of I-2 by reaction with I- was investigated in order to evaluate a mechanistic model. Separate systems for evaporation and absorption of It were studied, The overall mass transfer coefficient increased from 2 x 10(-4) to 2.5 x 10(-3) cm/s as I- concentration increased from 10(-4) to 10(-1) M. At I-concentrations greater than 10(-1) M, the interfacial transfer of I-2 was gas-side limited. The model gave a good representation of these results.