The Slowest Step

[YuditGaribay3J]

I know what the slowest step is, but I'm still having trouble how you find the slowest step?

[Andreas Krumbein 1L]

It will almost always tell you which step is the slowest since the speed of each elementary step is determined experimentally.

[JonathanM]

It will definitely tell you, but also remember that when making rate laws if a reactant in the slowest step is an intermediate compound you have to replace it with previous reactants that made the intermidiate.

[Raashi Chaudhari 3B]

The slow step is normally indicated. The reaction rate is based off the slow step so its important to use that one and identify it when writing your rate law. As mentioned above the slow step may include an intermediate, so you would have to work out the substitution of that compound in your actual rate law.

[Pranav Daggubati 3C]

The speed of each step is usually given. However, if looking to figure out experimentally, what we would do is get the reactants and react a small amount of one with an excess of others to study the rate of that one reactant, and repeat for all the reactants. Then, examine what the slowest rate is and see what it is reacting with. This will lead to understanding the mechanism and therefore the speed of steps can be determined.

[Neal_Agarwal_3B]

The slow step in an elementary reaction will just be the single mechanism. In a multistep mechanism the slow step can be found by deriving the rate laws of all the individual steps and then the rate law that corresponds to the overall reaction rate law is the slow step. The slow step determines the reaction rate in all of these scenarios.

[Mina Tadros 3L]

The slowest step is typically given to you. If you are given a diagram, the slow step would be the one with the greatest activation energy.