Including the intermediate

[Fernell_Orellana_3C]

Hello,

Whenever writing out the rate laws for a particular reaction, especially in the case of a multiple step reaction, the intermediate is never included, right? Rate laws exclude intermediates, and whenever the slow step has an intermediate, how would one go about excluding it?

[306060519]

Yes, when you write the rate laws, you always cancel out the intermediates. This is because they cancel out when you are adding the equation together.

[Sophia Lim 2A]

In the context of rate laws and reaction mechanisms, intermediates are typically excluded from the rate law expression because they are often formed in one step and consumed in a subsequent step of the reaction mechanism. This means they do not appear in the overall balanced equation for the reaction. When considering a multi-step reaction mechanism, the rate-determining step (often referred to as the slow step) is the step that limits the overall rate of the reaction. This step typically involves the formation or consumption of one or more reactive species, including intermediates.

[Lexi Brownsberger 2E]

To easily identify intermediates, you can look for molecules that show up as a product and then are fully used up as a reactant. These will not be included in the rate law since they are fully consumed in the overall reaction.

[Denise Mora 1C]

Yes, when writing the rate law for the overall reaction do not include the intermediate. Only in some cases, intermediates may appear in the rate law for the overall reaction, especially if they are involved in the rate-determining step. If the intermediate is formed and consumed in the rate-determining step, it may appear in the rate law for the overall reaction. If the intermediate is formed in a step but is not consumed until a subsequent step then it would not be included in the rate law for the overall reaction.