Explaining Le Chatelier's Principle
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Explaining Le Chatelier's Principle
Hi! Is there anyone who could give me a summary or concise explanation of Le Chatelier's Principle? I am still confused about whether pressures/concentrations increase versus decrease, and so on. Thanks in advance!
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Re: Explaining Le Chatelier's Principle
If you change the concentration or partial pressure, the reaction will shift towards the side that has less. This means if you add reactants, the reaction will shift to the products, but if you take away reactants, the reaction will shift to the reactants.
If you increase the pressure of the entire system (or decrease the volume), which way the reaction will shift depends on how many moles of gas of the product and reactants there are, because the reaction would shift to the side with less moles of gas. If you decrease the pressure/increase volume, the reaction will shift to the side with more moles of gas.
If you add heat, which way the reaction shifts depends on whether the reaction is endothermic or exothermic. If the reaction is endothermic and you add heat, the reaction will shift right to the products. If the reaction is exothermic and you add heat, the reaction will shift left to the reactants. You can remember by thinking of heat as a product (exothermic) or reactant (endothermic) and then following the first rule of adding or taking away reactants or products.
If you increase the pressure of the entire system (or decrease the volume), which way the reaction will shift depends on how many moles of gas of the product and reactants there are, because the reaction would shift to the side with less moles of gas. If you decrease the pressure/increase volume, the reaction will shift to the side with more moles of gas.
If you add heat, which way the reaction shifts depends on whether the reaction is endothermic or exothermic. If the reaction is endothermic and you add heat, the reaction will shift right to the products. If the reaction is exothermic and you add heat, the reaction will shift left to the reactants. You can remember by thinking of heat as a product (exothermic) or reactant (endothermic) and then following the first rule of adding or taking away reactants or products.
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Re: Explaining Le Chatelier's Principle
This diagram is helpful for thinking about Le Chatelier's Principle!
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Re: Explaining Le Chatelier's Principle
Le Chattelier's Principle states that chemical reactions adjust so as to minimize the effect of any changes. Therefore, whenever something is done to a reaction a reaction will respond in the opposite way. For instance, if you increase the amount of reactant, the reaction will adjust to remove that extra reactant you added in by using it making the forward reaction favored. Remembering this concept may allow you to not have to memorize all the effects of changing concentration, pressure, etc.
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Re: Explaining Le Chatelier's Principle
Simply, Le Chatelier's principle is just the reaction balancing itself after a disturbance. By considering the changes in the equilibrium constant and other properties of gases and solutions, you can intuitively work out how the reaction balances itself without having to memorize anything.
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Re: Explaining Le Chatelier's Principle
In essence, Le Chatlier's Principle explains that when a system experiences a disturbance it will work to overcome that disturbance and restore the system to a state of equilibrium.
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Re: Explaining Le Chatelier's Principle
The Le chatelier's Principle is essentially a migration of pressure on the solution. In this idea, the reaction will do the least to mitigate the harmfulness of the change of environment. Henceforth, it is the principals of how reactions respond to such changes.
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Re: Explaining Le Chatelier's Principle
I think of Le Chatelier's Principle that the reaction will try to undo the disturbance caused to it, so maintain its equilibrium.
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Re: Explaining Le Chatelier's Principle
Le Chatelier's principle is basically how equilibrium will shift to oppose the change caused by the disturbance.
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Re: Explaining Le Chatelier's Principle
Le Chatelier's principle states that the reaction will try to minimize the effects of changes made upon it. So try to think of this in terms of correcting a change. So if you add reactants to a system, you will make more products to counter the addition of reactants. The same thing happens with pressure. If you increase pressure by decreasing volume, the side of your reaction with more moles of gas will increase in pressure faster than the side with fewer moles of gas. Therefore the reaction will favor the side with the fewer moles of gas because P= concentration x RT. If you want to increase the pressure of the side with fewer moles of gas and decrease the pressure with more moles of gas (and you are not changing temperature), you can change their concentrations by producing either more products or more reactants.
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Re: Explaining Le Chatelier's Principle
jessicaosuna_1F wrote:This diagram is helpful for thinking about Le Chatelier's Principle!
ooooo very helpful diagram! thank you!!
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Re: Explaining Le Chatelier's Principle
Lillian Ma 1I wrote:If you change the concentration or partial pressure, the reaction will shift towards the side that has less. This means if you add reactants, the reaction will shift to the products, but if you take away reactants, the reaction will shift to the reactants.
If you increase the pressure of the entire system (or decrease the volume), which way the reaction will shift depends on how many moles of gas of the product and reactants there are, because the reaction would shift to the side with less moles of gas. If you decrease the pressure/increase volume, the reaction will shift to the side with more moles of gas.
If you add heat, which way the reaction shifts depends on whether the reaction is endothermic or exothermic. If the reaction is endothermic and you add heat, the reaction will shift right to the products. If the reaction is exothermic and you add heat, the reaction will shift left to the reactants. You can remember by thinking of heat as a product (exothermic) or reactant (endothermic) and then following the first rule of adding or taking away reactants or products.
This explanation was very helpful but I wanted to ask about the second paragraph. If you decreased the pressure, why would the reaction shift to the side with more moles of gas??
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Re: Explaining Le Chatelier's Principle
jessicaosuna_1F wrote:This diagram is helpful for thinking about Le Chatelier's Principle!
Thank you! This diagram is super helpful.
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Re: Explaining Le Chatelier's Principle
I think about it as a scale, as one side increases and gets heavier the other side goes up indicating an increase on that side.
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Re: Explaining Le Chatelier's Principle
I like to think of Le Chatelier's as minimizing the effects of a change in the system on the equilibrium. Le Chatelier works to get Q closer to K. If you think about it this way, it helps see which way the reaction goes. More reactants makes Q smaller, so to get back to K, there needs to be more products.
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