Le Chatelier Principle

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Tracy Tolentino_2E
Posts: 140
Joined: Sat Sep 07, 2019 12:17 am

Le Chatelier Principle

Postby Tracy Tolentino_2E » Sun Jan 19, 2020 11:29 pm

Why does only a change in temperature affect K and not pressure or concentration? How does Le Chatelier principle apply to this if the principle sees the direction of the reaction due to changes?

Althea Zhao 1B
Posts: 101
Joined: Mon Jun 17, 2019 7:24 am

Re: Le Chatelier Principle

Postby Althea Zhao 1B » Mon Jan 20, 2020 10:47 am

If you change partial pressure or concentration, the reaction will shift to maintain the original equilibrium constant. A change in temperature changes reaction rates.

Posts: 104
Joined: Wed Sep 11, 2019 12:16 am

Re: Le Chatelier Principle

Postby 805394719 » Mon Jan 20, 2020 11:12 am

I think temperature changes the equilibrium constant because it favors either endothermic or exothermic reactions. For example, if we have a reaction A + B --> C, and the forward reaction is endothermic, changing the temperature will favor the forward reaction. As the equilibrium constant indicates whether there is more product or reactant at equilibrium (K greater than or smaller than 1), if the forward reaction is endothermic and is favored, there will be more products at equilibrium than reactants. If the forward reaction is exothermic and the temperature is increased, then the amount of reactants will increase at equilibrium relative to the products since the reverse reaction which is endothermic is favored. Changing the pressure and the volume does not change the relative concentrations of the products and reactants because the system shifts to one side or the other to counteract this change and there will be no change in the ratio of products and reactants at equilibrium. At constant temperature, changing the equilibrium concentrations does not affect the equilibrium constant because the equilibrium constants are not affected by concentration changes.

Emily Burghart 1k
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Joined: Wed Sep 18, 2019 12:17 am

Re: Le Chatelier Principle

Postby Emily Burghart 1k » Mon Jan 20, 2020 11:32 am

When considering temperature, pressure, and concentration, it is important to note that pressure and concentration both only change where equilibrium lies on the equilibrium constant. If you were to increase pressure or concentration in one part of the equation, pressure or concentration would decrease somewhere else to maintain balance.

However, if you change temperature, the K value at equilibrium is no longer the same.

Natalie Benitez 1E
Posts: 100
Joined: Fri Aug 02, 2019 12:15 am

Re: Le Chatelier Principle

Postby Natalie Benitez 1E » Mon Jan 20, 2020 12:10 pm

A change in pressure or concentration only effects the direction the reaction is going because it will shift in direction to maintain equilibrium. However, a change in temperature effects the rates the reactions are occurring, thus, effecting the K value.

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