Test tomorrow, last hope

[Endoapp24]

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Hey guys (and gals 😉
I'm taking the DAT tomorrow and I'm feeling pretty good about everything but one thing.

Two things
First:
In gen chem, changing concentrations/pressure/temperature all shift the equilibrium but only temperature changes K, I get that. But I'm having a hard time distinguishing when a question specifically refers to the changing of K (where the answer would only be change in temperature or none of the above), or simply a shifting of equilibrium according to le Chateliers. I dont have specific questions in mind (it's been an ongoing issue), but something like:

Consider the following reaction at equilibrium:

2CO(g) + O2(g)

2CO2(g)

Hº = -566kJ
Which of the following would increase the amount of CO2 present?

-How do I know that its talking about Le Chat, when the reaction is at equilibrium and technically the only thing that will change that is temperature. (correct answer for this problem is: adding more CO). Of course this issue only applies when the question specifically states that the reaction is at equilibrium, if it's not at equilibrium then the choice is easy. My point up to know has been that Temperature is the only answer if it SPECIFICALLY states equilibrium constant.

Second:
Just to make sure both catalysts and temperature change k for rate laws correct? for something like Rate = K[A], adding a catalyst would increase the rate by increasing K?

Appreciate it 🙂

 

[rolltide15]

It's basically asking you what can you do to make more CO2. They include the delta H because it can change the equilibrium if more heat is added but since you want to increase the amount of CO2 you have to increase either O2 gas or CO gas because Le Chat principle opposes the force you apply to it. So the temperature has nothing to do with this question.

 

[KoonS]

Negative delta H mean the reaction is exothermic, heat is on the product side, so if you decrease the temperature the equilibrium will shift to the right to make more product, CO2 in this case, to offset the change.
Idk if this is what you are trying to ask, the way you worded your question is so confusing.

 

[DrLTD]

Good luck on your test!