notevenintheuk
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can someone please explain it to me. I would really appreciate it since im struggling
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CoolCavy
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What subject is this for?
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notevenintheuk
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chemistry (and I'm sorry i couldn't find the chemistry forum )
(Original post by CoolCavy)
What subject is this for?
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CoolCavy
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(Original post by notevenintheuk)
chemistry (and I'm sorry i couldn't find the chemistry forum )
That's quite alright :yep: have moved it there now ⚗️
CheeseIsVeg does chemistry she might be able to help :yes:
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anikaxox555
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if a reaction at equilibrium is subjected to a change in temperature pressure or concentration the equilibrium will move to counteract the change

that’s the official definition, but basically a reaction at equilibrium wants to stay at equilibrium no matter what!
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notevenintheuk
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t
(Original post by anikaxox555)
if a reaction at equilibrium is subjected to a change in temperature pressure or concentration the equilibrium will move to counteract the change

that’s the official definition, but basically a reaction at equilibrium wants to stay at equilibrium no matter what!
thank you. so basically, i just need to balance the equation?
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CheeseIsVeg
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(Original post by CoolCavy)
That's quite alright :yep: have moved it there now ⚗️
CheeseIsVeg does chemistry she might be able to help :yes:
Hey thanks Cavsicle :hugs:
(Original post by notevenintheuk)
t

thank you. so basically, i just need to balance the equation?
You always need to work with a balanced equation. Check it is balanced and then study it.
Which way is endo/exothermic? How many molecules of gas do you have on either side?
What conditions are you changing and how is the system likely to react?

If you want help on a particular question you need to give us more information.
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Kallisto
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(Original post by notevenintheuk)
can someone please explain it to me. I would really appreciate it since im struggling
Seems to be a general question. As anikaxox555 wrote if a reaction at equilibrium is subjected to a change outside, the equilibrium has to be changed too.

For examples:

- if the temperature in this equilibrium is increased, the exothermic reaction is reduced.
- if pressure increases, the reaction with the least volume is benefited.

In these two examples, you can see the reaction prompts an opposite to response, the equilibrium always kicks back.
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Kian Stevens
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Essentially, the system will do the opposite to what you do to it, and the equilibrium will shift accordingly.
This is Le Chatelier's Principle: if a system in dynamic equilibrium undergoes a change, the system's equilibrium will shift to oppose it.
Let's say we have the following exothermic system: A(g) + 3B(g) \rightleftharpoons C(g) + D(g).

If the forward reaction is exothermic and releases heat, then the reverse reaction is endothermic and absorbs heat.
Since the system already is already releasing heat, it doesn't want to be heated up any more. So, if you were to heat it up, the equilibrium would shift to the left (in the endothermic direction) to oppose the addition of heat by absorbing it. In other words, the system attempts to cool itself down.
If you were to cool the system down, the opposite would happen: the equilibrium would shift to the right (in the exothermic direction) to oppose the reduction of heat by releasing more. In other words, the system attempts to heat itself up.

The same logic applies to increasing and decreasing the concentrations of products and reactants in the system.
Let's say you reach equilibrium, and then add more A or B to the system. The equilibrium will shift to the right, as it opposes the increase of reactants by producing more products. This is the same logic for if C and D were removed from the system.
However, let's say you reach equilibrium, and then add some more C or D to the system. The equilibrium will shift to the left this time, to oppose the increase of products by producing more reactants. Similarly, this is the same logic for if A and B were removed from the system.

Finally, the same logic applies to increasing and decreasing the system's pressure.
As you can see, there are more gaseous moles of reactants than products (there are a total of 4 moles of reactants, and only a total of 2 moles of products). Because of this, increasing the system's pressure will shift the equilibrium to the right, essentially opposing the change by favouring the formation of a lower pressure system.
However, decreasing the system's pressure will shift the equilibrium to the left, as the system will oppose the change by favouring the formation of a higher pressure system.
As you may notice, having a system with equivalent amounts of gaseous reactants and products will mean that changing the system's pressure won't have an effect.
Last edited by Kian Stevens; 1 year ago
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