Evidences
suggest that this reaction takes place in two steps
(1) H2O2 + I– ® H2O + IO–
(2) H2O2 + IO– ® H2O + I– + O2
Both the steps are bimolecular elementary reactions Species IO- is
called as an intermediate since it is formed during the course of the
reaction but not in the overall balanced equation The first step, being
slow, is the rate determining step Thus, the rate of formation of
intermediate will determine the rate of this reaction