Catalysts vs. Intermediates

Arrhenius Equation: $\ln k = - \frac{E_{a}}{RT} + \ln A$

EthanPham_1G
Posts: 104
Joined: Sat Jul 20, 2019 12:17 am

Catalysts vs. Intermediates

What is the difference between a catalyst and an intermediate. Can a catalyst also be an intermediate and vice versa?

Ally Huang- 1F
Posts: 103
Joined: Thu Jul 25, 2019 12:16 am

Re: Catalysts vs. Intermediates

A catalyst is inputted into the reaction as a reactant and comes out unchanged as a product. An intermediate is formed as a product in one step and then used up as a reactant in a proceeding step. Therefore, I don't think a catalyst can be an intermediate and vice versa.

bellaha4F
Posts: 104
Joined: Wed Sep 18, 2019 12:20 am

Re: Catalysts vs. Intermediates

an intermediate is seen in the product side first and disappears later, while a catalyst is added first to the reactant side and than reappears later on the product side.

Sofia Barker 2C
Posts: 101
Joined: Wed Sep 18, 2019 12:21 am

Re: Catalysts vs. Intermediates

Intermediates are used up in a reaction, while catalysts are not. However, neither show up in the overall reaction for a chemical reaction because they are found on both the product and reactant side of different steps of a reaction and thus cancel out. Catalysts appear as reactants in one step and again as products in the next step because they aren't used up, whereas intermediates appear as products in one step and reactants in the next step because they are formed and used to help form a different product.
Take this multi-step reaction as an example.

step 1: A + B --> C + D
step 2: D + E --> B + F
overall reaction: A + E --> C + F

The intermediate would be D because it is formed in the first step and subsequently used up in the next one.
The catalyst would be B because, while it enters the reaction as a reactant, it is ultimately reformed as a product that can be used to catalyze a different reaction.
As you can see, the overall reaction doesn't include either of the two.

jisulee1C
Posts: 149
Joined: Thu Jul 25, 2019 12:17 am

Re: Catalysts vs. Intermediates

A catalyst cannot be an intermediate because intermediates are produced by the reaction and used up in another following step of the reaction mechanism while a catalyst is not used up during the reaction. Because a catalyst is not used up, a small amount can be used to speed up the reaction and continue to be reused, this is helpful for real life applications where chemical reactions are sped up.

Nathan Nakaguchi 1G
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Re: Catalysts vs. Intermediates

A catalyst is something that lowers the activation energy of a reaction and leaves K(equilibrium) the same, a catalyst should appear on both sides of the total net reaction, while an intermediate is an actual product between steps of the reaction that will not appear in the final net reaction.

ABombino_2J
Posts: 102
Joined: Thu Jul 11, 2019 12:15 am

Re: Catalysts vs. Intermediates

A catalyst exits in the beginning of a set of reactions and also comes out at the end of a set of reaction, so it is used up and then produced. An intermediate is formed and then used up.

Lizette Noriega 1H
Posts: 105
Joined: Wed Sep 18, 2019 12:15 am

Re: Catalysts vs. Intermediates

An intermediate is produced in the first step then later consumed in the second step while the catalyst is consumed in the first step then produced in the second.

Tiffany_Chen 2K
Posts: 106
Joined: Fri Aug 30, 2019 12:15 am

Re: Catalysts vs. Intermediates

Intermediates will not show up in the final product, catalysts will as it is not degraded.