Abstract
Reactions of iodine in aqueous phase were studied by a concentration relaxation method. From the result of the present investigation, the mechanism of the absorption of iodine in air by aqueous sodium hydroxide solution is as follows:
(Step 1) Molecular iodine in air dissolves into the aqueous phase through the gas-liquid interface according to Henry''s law.
(Step 2) Instantaneous reversible reactions take place in the aqueous phase and HIO, I- and I3- form.
(Step 3) HIO formed by the above reaction is consumed gradually and IO-3 forms, while the instantaneous reversible reactions of step 2 are in equilibrium at any instant.
Overall consumption rate of HIO can be approximated by the rate equation of the second-order reaction with respect to HIO.
