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Rate-determining step

Posted: Thu Mar 12, 2020 6:20 pm
How can you identify which step of the reaction mechanism is the slowest step? Or will this just be given in the problem itself?

Re: Rate-determining step

Posted: Thu Mar 12, 2020 6:42 pm
Identifying the rate limiting step can be proposed / guessed from the reaction rate equation. Depending on the question, it may also be given in the problem itself.

Re: Rate-determining step

Posted: Thu Mar 12, 2020 7:35 pm
Usually the slow step will be given, but you might be given data about the different steps and have to analyze it to determine the rate determining step

Re: Rate-determining step

Posted: Sat Mar 14, 2020 1:42 pm
They usually tell us which is the slow and fast step.

Re: Rate-determining step

Posted: Sat Mar 14, 2020 2:05 pm
It will probably be given to you in the question!

Re: Rate-determining step

Posted: Sat Mar 14, 2020 2:25 pm
Eileen Si 1G wrote:How can you identify which step of the reaction mechanism is the slowest step? Or will this just be given in the problem itself?

If you are given the differential rate law and a proposed reaction mechanism (with its elementary steps), you can determine which elementary step is rate-determining by seeing which elementary step has the proposed differential rate law. If you are not given the differential rate law, then you will likely be told which step is the slowest step, and you will (likely) have to determine the differential rate law.

Re: Rate-determining step

Posted: Sat Mar 14, 2020 11:13 pm
If they give you a rate law and ask to find the rate determining step out of given elementary steps, look for the step that has all of the molecules in the given rate law/ match them.

Re: Rate-determining step

Posted: Sun Mar 15, 2020 6:37 am
Isn't there a way to tell which is the rate determining step by looking at phases or am I just mistaken?