Reactions of iodine in aqueous solutions containing sodium hydroxide

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 [formula omitted] form. (Step 3) HIO formed by the above reaction is consumed gradually and [formula omitted] 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. © 1974, The Society of Chemical Engineers, Japan. All rights reserved.