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#1
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Is there any particular explanation as to why this principle works at all? I've looked around a bit on the internet and haven't really found any site that gives a proper explanation as to why it really works.

Also, my teacher mentioned something about it not being applicable in certain situations. Could any tell me what these situations are and why it doesn't work in these cases?

Thanks for helping!
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L'Evil Fish
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Can only work in a closed dynamic system. If a reaction is reversible it'll occur.

This might be totally wrong, but maybe it's like a body's homeostasis. It's in a position it likes, if you get hot, your body cools you down, or a reaction moves in endothermic direction.

Perhaps?
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(Original post by L'Evil Fish)
Can only work in a closed dynamic system. If a reaction is reversible it'll occur.

This might be totally wrong, but maybe it's like a body's homeostasis. It's in a position it likes, if you get hot, your body cools you down, or a reaction moves in endothermic direction.

Perhaps?
I think it was something to do with large changes in a system and how it only applies to small changes, but I'm not too sure about that . I'll try and get back to him about it after the holidays.

Yes, but what makes it return to it's original state? The body stays at a constant temperature in order for the cells to function properly due to the enzymes and other stuff I probably don't know about, but what makes it so that a chemical reaction even has this 'liked' position in the first place? :confused:

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L'Evil Fish
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(Original post by Arithmeticae)
I think it was something to do with large changes in a system and how it only applies to small changes, but I'm not too sure about that . I'll try and get back to him about it after the holidays.

Yes, but what makes it return to it's original state? The body stays at a constant temperature in order for the cells to function properly due to the enzymes and other stuff I probably don't know about, but what makes it so that a chemical reaction even has this 'liked' position in the first place? :confused:

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It's a stable position perhaps? A ratio of products to reactants that makes a stable system?

Again. I'm just speculating, no clue.
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EierVonSatan
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Science isn't all that great at answering these kinds of deep ''why'' questions :p:

The principle describes what takes place so we can better understand how such systems behave in given conditions and changes made to them. It's not an explanation for why it happens.
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F1's Finest
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It works to oppose the changes you made (by you disturbing the equilibrium).
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swanderfeild
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I think it works because of need to preserve the constant. For instance take concentration:
Kc = [Reactants]/[Products] where Kc is a constant.
Now if you increase concentration of products, concentration of reactants must increase so that Kc doesn't decrease and vice versa. Same principle applies with pressure (keeping Kp).

Thats how I understood it anyway.
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fizzers
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If you think about it, it kind of is like negative feedback in homeostatis (echoing previous posters). I'd like to know why as well if there's an explanation!
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L'Evil Fish
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(Original post by swanderfeild)
I think it works because of need to preserve the constant. For instance take concentration:
Kc = [Reactants]/[Products] where Kc is a constant.
Now if you increase concentration of products, concentration of reactants must increase so that Kc doesn't decrease and vice versa. Same principle applies with pressure (keeping Kp).

Thats how I understood it anyway.
This is what I was thinking of! The Kc.

But then why a system has a certain Kc is the question.
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swanderfeild
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(Original post by L'Evil Fish)
This is what I was thinking of! The Kc.
But then why a system has a certain Kc is the question.
Wouldn't a constant naturally arise due to nature of equilibrium? I mean because at equilibrium point rate of forward reaction must equal rate of backward reaction. If reactants are A and products are B, then k1[A]=k2[B].
k1/k2=[A]/[B] and since k1/k2 is a constant that can be said to be equilibrium constant.
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(Original post by L'Evil Fish)
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(Original post by fizzers)
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(Original post by swanderfeild)
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Second law of thermodynamics maybe? I'm just guessing here, but it seems to provide a 'nice enough' explanation for why the system has a certain equilibrium constant at a certain rate (as this is where it has maximum entropy, so that must be where the thermodynamic equilibrium is?)

This may also have something to do with it.
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L'Evil Fish
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(Original post by swanderfeild)
Wouldn't a constant naturally arise due to nature of equilibrium? I mean because at equilibrium point rate of forward reaction must equal rate of backward reaction. If reactants are A and products are B, then k1[A]=k2[B].
k1/k2=[A]/[B] and since k1/k2 is a constant that can be said to be equilibrium constant.
Hmmmm...
(Original post by Arithmeticae)
Second law of thermodynamics maybe? I'm just guessing here, but it seems to provide a 'nice enough' explanation for why the system has a certain equilibrium constant at a certain rate (as this is where it has maximum entropy, so that must be where the thermodynamic equilibrium is?)

This may also have something to do with it.
I shall have a read later! I probably won't understand anything.
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(Original post by Arithmeticae)
Second law of thermodynamics maybe? I'm just guessing here, but it seems to provide a 'nice enough' explanation for why the system has a certain equilibrium constant at a certain rate (as this is where it has maximum entropy, so that must be where the thermodynamic equilibrium is?)
Dug around a little and this seems to explain it quite well. (I'm not familiar enough with those principles/ideas to know if they actually explain it or not but it appears so with my basic understanding :rolleyes:)
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(Original post by fizzers)
Dug around a little and this seems to explain it quite well. (I'm not familiar enough with those principles/ideas to know if they actually explain it or not but it appears so with my basic understanding :rolleyes:)
Yes, I ran into this as well. The whole 'Gibbs free energy' thing seems to be a restatement of the second law of thermodynamics which suggest that the system will eventually settle into an equilibrium with maximum entropy, which is why they have a fixed Kc.

Thanks for helping!
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fizzers
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(Original post by Arithmeticae)
Yes, I ran into this as well. The whole 'Gibbs free energy' thing seems to be a restatement of the second law of thermodynamics which suggest that the system will eventually settle into an equilibrium with maximum entropy, which is why they have a fixed Kc.

Thanks for helping!
Aha, that's what I thought as well! Looking into the fluctuation-dissipation theorem right now.

No worries! I'm hardly helping at all and I'm very curious myself too (kind of surprised I never thought about it actually)
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#16
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In a strangely curious mood today, appreciate it if anyone could help me with this. :puppyeyes:
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