Page 1 of 1

Slow Step

Posted: Fri Mar 08, 2019 5:57 pm
by ian_haliburton_1f
Can someone explain to me why the slowest step in a reaction process determines the overall rate law for the reaction?

Re: Slow Step

Posted: Fri Mar 08, 2019 6:08 pm
by Lopez_Melissa-Dis4E
You can only go as fast as your slowest reaction, therefore it is determines your overall rate law.

Re: Slow Step

Posted: Fri Mar 08, 2019 8:21 pm
by Eric Quach 1C
Another way to put it would be that there is a bottleneck at the slow step. For example if there are 3 steps in a reaction and step 2 is the slow step, it doesn't matter if step 1 and 3 are almost instantaneous as step 2 must finish occurring before step 3 which completes the reaction.

Re: Slow Step

Posted: Sat Mar 09, 2019 3:10 am
by Celine Cheng 1H
What would happen if you have 2 slow steps? Is the slower step still the determining rate? Is having more than 2 slow steps possible?

Re: Slow Step

Posted: Sat Mar 09, 2019 10:44 am
by Chris Freking 2G
Celine Cheng 1H wrote:What would happen if you have 2 slow steps? Is the slower step still the determining rate? Is having more than 2 slow steps possible?


You can still have multiple "slow" reactants, but ultimately the slowest one will still determine the overall rate law.

(An extremely small bottleneck will still be a bottleneck for another small bottleneck)

Re: Slow Step

Posted: Sat Mar 09, 2019 9:30 pm
by Dong Hyun Lee 4E
How do you determine the slowest step then? is it the lowest k value?