Kinetics of the reaction of OH with I2

Abstract

A steady-state system involving the photolysis of HONO as a source of OH radicals was used to obtain a rate constant for the OH + I₂ reaction at 1 atm and 294 K. The value obtained, k=(2.1 ± 1.0)× 10^–10 cm³ molecule^–1 s^–1(relative to the rate constant for OH + C₂H₄, 8.0 × 10^–12 cm³ molecule^–1 s^–1), was determined from the suppression of [OH] at steady state in the presence of I₂ at various concentrations. This reaction probably produces gaseous hypoiodous acid, which was unstable under the experimental conditions employed, resulting in regeneration of I₂.