I know the reaction is exothermic,how do I tell what the rate limiting step is?
ID: 575930 • Letter: I
Question
I know the reaction is exothermic,how do I tell what the rate limiting step is?
20. A team of intrepid graduate students in the lab of Rick T. Cat is working to elucidate a much sought- after mechanism for a very important reaction regarding the decomposition of ozone (O3 in the presence of NO (Z). They collect the following data using reaction progress kinetic analysis: Reaction Progress Each peak represents a step in the mechanism. Is this reaction endothermic or exothermic, and what is the rate-limiting step in the forward direction? Rate-limiting step first first A. B. C. D. E. exothermic endothermic endothermic exothermic endothermic second thirdExplanation / Answer
The rate determining step is the one which has the highest energy transition. The step with highest energy may not be the rate determining step always. It depends on the difference in the potential energies of the starting material and the intermediate. Here this difference is maximum for step 1 as we can see in the figure. So step 1 is rds.