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Le chatilier's principle says that increasing the temperature of an endothermic reaction will drive the reaction forward and increase the equilibrium constant. well thats great but i'm confused about this...
we know that the equilibrium constant is derived from the rate law. for example, for the reaction A+B->C+D, the equilibrium expression comes from the fact that
rate forward reaction = rate reverse reaction
k(forward)*[A](B) = k(reverse)*[C][D]
and therefore,
k(forward) / k(reverse) = [C][D] / [A](B)
This expression equals the equilibrium constant:
K(eq) = k(forward) / k(reverse) = [C][D] / [A](B)
why doesn't increasing temperature increase the forward and reverse rate to the same extent? the arrenhieus equation says that the rate constant of a reaction increases with increasing temperature. therefore, wouldn't we predict that BOTH the forward and reverse reaction rates for any reaction would increase with increasing temperature? I'm so confused as to why Le Chats principle predicts that, for example, increasing the temperature of an endothermic reaction will drive it forward. wouldn't the k(forward) and k(reverse) both increase to the same extent, and therefore the equilibrium would not change, meaning that there would be no change in the concentrations of the reactants and products precisely because the forward and reverse reaction rates increased the same amount.
I feel like i'm missing something important here. I would like to understand the chemistry going on here rather than just memorize the effects of temperature changes on exo/endothermic reactions.
we know that the equilibrium constant is derived from the rate law. for example, for the reaction A+B->C+D, the equilibrium expression comes from the fact that
rate forward reaction = rate reverse reaction
k(forward)*[A](B) = k(reverse)*[C][D]
and therefore,
k(forward) / k(reverse) = [C][D] / [A](B)
This expression equals the equilibrium constant:
K(eq) = k(forward) / k(reverse) = [C][D] / [A](B)
why doesn't increasing temperature increase the forward and reverse rate to the same extent? the arrenhieus equation says that the rate constant of a reaction increases with increasing temperature. therefore, wouldn't we predict that BOTH the forward and reverse reaction rates for any reaction would increase with increasing temperature? I'm so confused as to why Le Chats principle predicts that, for example, increasing the temperature of an endothermic reaction will drive it forward. wouldn't the k(forward) and k(reverse) both increase to the same extent, and therefore the equilibrium would not change, meaning that there would be no change in the concentrations of the reactants and products precisely because the forward and reverse reaction rates increased the same amount.
I feel like i'm missing something important here. I would like to understand the chemistry going on here rather than just memorize the effects of temperature changes on exo/endothermic reactions.