Question

The following mechanism has been suggested for the reaction: H2O2+2H+2I--->I2+H2O H2O2+I--->HOI+OH (SLOW) OH+H--->H2O (FAST) HOI+H+I--->I2+H2O (FAST) Identify the molecularity of the rate determining step. please explain why.

Answer 1

reaction is

H2O2+2H+2I--->I2+H2O

Mechanism is

H₂O₂    +    I^-   --->    HOI   +   OH (SLOW)

OH+H--->H2O (FAST)

HOI+H+I--->I2+H2O (FAST)

molecularity of the reaction is nothing but a number of molecules or ions that participate in the slow step because slow step is the rate determining step

here rate determining step

H₂O₂    +    I^-   --->    HOI   +   OH^-

no of molecules participated here is 2

molecularity is 2