Bootcamp fact about Catalysts?

[RuffDay]

I was doing a problem on boot camp, and it was asking what will decrease the Ke of N2(g) + 3H2(g) ⇌ 2NH3(g) ; ΔH° = -92.22 kJ•mol-1. One of the choices were adding an Iron catalyst and the other was increasing the temperature.

I understand why increasing the temperature will decrease the Ke because the reaction is exothermic, and in order for it to reach equilibrium.. the reaction would have to go to the left. However, I am having a hard time understanding one of the solution for bootcamp, where it mentioned that a catalyst does not ever change Ke?

Why is that? I thought the two things that can change the equilibrium of Ke is temperature and activation energy. Wouldn't adding a catalyst decrease the activation energy, and that will cause K to increase? I would understand if the explanation tells us that catalyst would cause K to increase here, but instead it says that catalyst has no effect.

Am I missing something here?

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[Futuredentista62]

"A catalyst speeds up the forward and back reaction to the same extent. Because adding a catalyst doesn't affect the relative rates of the two reactions, it can't affect the position of equilibrium.

For a dynamic equilibrium to be set up, the rates of the forward reaction and the back reaction have to become equal. A catalyst speeds up the rate at which a reaction reaches dynamic equilibrium."

http://www.chemguide.co.uk/physical/equilibria/lechatelier.html

 

[RuffDay]

I thought on Chad's notes that it does affect the K.

 

[Futuredentista62]

Look at the first video for Equilibrium. Chad says the only thing that changes them is temperature.

 

[RuffDay]

Look at the first video for Equilibrium. Chad says the only thing that changes them is temperature.

Thanks!