Q > K, Q< K

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Melody Haratian 2J
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Q > K, Q< K

Postby Melody Haratian 2J » Sun Jan 17, 2021 12:50 pm

Can someone explain what happens when Q> K and Q< K?
I’m having a bit of trouble understanding the concept.
Thanks!

Silvi_Lybbert_3A
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Re: Q > K, Q< K

Postby Silvi_Lybbert_3A » Sun Jan 17, 2021 12:56 pm

When Q>K that means that there are more products than there should be. This is because if you look at what Q and K represent, it is the ratio of products/reactants. So if Q is larger than K, it means that there is a larger numerator and therefore more products than there should be at equilibrium, K. Because K is equilibrium and where the reaction wants to be, the reaction will use up these extra products in the reverse reaction (proceeding left in the direction towards reactants) to return the reaction to the correct ratio of products/reactants. Note: only the ratio has to be the same, not the concentrations; for example, if you add products, the overall concentrations of both products and reactants will be larger in the end but the ratio will return to the equilibrium ratio when products get used up and become reactants.
When Q<K, the reaction proceeds towards the products in the forward direction because Q being less than K shows their are more reactants than there should be and they will be used up until equilibrium ratio returns. Le Chatelier's principle highlights these changes because the reaction wants to minimize the effect of a change (such as increasing concentrations of reactants or products).

Racquel Fox 2I
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Re: Q > K, Q< K

Postby Racquel Fox 2I » Sun Jan 17, 2021 1:14 pm

When Q>K, the reaction shifts towards the reactants, and when Q<K, the reaction shifts toward the products. There's a tip where if you write the K before the Q, the arrow points towards the direction of the shift: K<Q, shift toward reactants; K>Q, shift toward products.

Sandy Lin 1L
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Re: Q > K, Q< K

Postby Sandy Lin 1L » Sun Jan 17, 2021 1:15 pm

K is calculated when the reaction is at equilibrium that is why it is a constant and will not change. Q can be calculated at any time during the reaction. The value of Q is compared with K to show which direction the reaction will proceed or if the reaction is at equilibrium. When Q>K then there are more products since products are in the numerator, the value of Q is greater. In order to adjust, the reaction will favor the reverse action to create more reactants. When Q<K the there are more reactants as Q is too small. To adjust this, the forward reaction will be favored so that more products can be made.

ellenulitsky Dis 1I
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Re: Q > K, Q< K

Postby ellenulitsky Dis 1I » Sun Jan 17, 2021 1:29 pm

K is the equilibrium constant and is present at equilibrium. However, when solving for Q, it can be happening at any point, hence why it can be greater, less, or equal to K. If it is less or greater than K then you know it is NOT at equilibrium yet. Hope this helps!

Massimo_Capozza_1G
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Re: Q > K, Q< K

Postby Massimo_Capozza_1G » Sun Jan 17, 2021 1:33 pm

Don't you calculate Q and K the same way? Q is just at any point in the reaction, and K is at equilibrium?

Blake Ballew 1H
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Re: Q > K, Q< K

Postby Blake Ballew 1H » Sun Jan 17, 2021 1:38 pm

Massimo_Capozza_1G wrote:Don't you calculate Q and K the same way? Q is just at any point in the reaction, and K is at equilibrium?

Yes, exactly like that. Q is basically just used to determine in which way the equation will head in order to reach the K value at equilibrium.

Nadya Higgins 3F
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Re: Q > K, Q< K

Postby Nadya Higgins 3F » Sun Jan 17, 2021 2:12 pm

K is the equilibrium constant, meaning that when you find it you have to put the equilibrium concentration of products over the equilibrium concentration of reactants. Q is the concentration of products over the concentration of reactants when the reaction is not in equilibrium. So, when Q is less than K, you are essentially saying that the ratio of products (P) over reactants (R) is less than what the ratio of what P over R would be if the reaction were in equilibrium. To me, that sounds like we're going need to make more products to increase the ratio. That's why the reaction is shifted to the right. More products need to be made in order to reach equilibrium.

If Q > K, then that means the ratio is higher than the equilibrium ratio. Sounds like the way to make Q approach K and get the system to equilibrium is to increase the reactants! (It makes sense if you think about P over R. The greater R is, the smaller the constant, while the greater P is, the larger the constant). If the reaction needs to increase the reactants, then that means it will be shifted to the left!

Matlynn Giles 2E
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Re: Q > K, Q< K

Postby Matlynn Giles 2E » Sun Jan 17, 2021 3:54 pm

Q>K means that the ratio is higher than the equilibrium ratio.

Sophia Kalanski 1A
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Re: Q > K, Q< K

Postby Sophia Kalanski 1A » Sun Jan 17, 2021 4:04 pm

when Q>K, there are more products than there should be and therefore the reaction will shift towards the reactants so that the Q can balance out to equal K. When Q<K, there are more reactants than there should be which is why the quotient is not equal to K so the reaction will shift towards and favor the products so that at some point Q can be the same as K

jasonfarrales3D
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Re: Q > K, Q< K

Postby jasonfarrales3D » Sun Jan 17, 2021 4:14 pm

Starting off, Q>K indicates that there are more products than reactants at the given time during this reaction. Thus, the formation of reactants is favored, so the reaction will shift towards the left (aka, the reverse reaction is favored. On the other hand, Q<K indicates that there are more reactants than products. In this case, the formation of products is favored, so the reaction will shift towards the right (aka, the forward reaction is favored). Hope this helps!

Lauren Sarigumba 1K
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Re: Q > K, Q< K

Postby Lauren Sarigumba 1K » Sun Jan 17, 2021 4:51 pm

When Q < K, the reaction will tend to favor the forward reaction and more products will be formed. When Q>K, the reaction will tend to favor the reverse reaction and more reactants will form. When Q = K, then equilibrium composition has been reached and there is no tendency to change in either direction.

jasmineculilap_3F
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Re: Q > K, Q< K

Postby jasmineculilap_3F » Sun Jan 17, 2021 5:19 pm

When Q < K, the reaction will favor the forward reaction, so there will be more products formed. When Q > K, the reverse reaction is favored with more reactants forming

Justin Zhang_1A
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Re: Q > K, Q< K

Postby Justin Zhang_1A » Sun Jan 17, 2021 5:24 pm

If Q > K, then the forward reaction is favored and produces more products. If Q < K, then the reverse reaction is favored with more reactants.

Zainab Jamali 1H
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Re: Q > K, Q< K

Postby Zainab Jamali 1H » Sun Jan 17, 2021 5:35 pm

IMG_2B91BABCC7E2-1.jpeg

This visual helps me remember in a really simple way! If Q>K then more reactants will form and if Q<K then more products will form in order to reach equilibrium where Q=K.

Melanie Lin 3E
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Re: Q > K, Q< K

Postby Melanie Lin 3E » Sun Jan 17, 2021 5:43 pm

Hi! When Q > K, the chemical reaction is not in equilibrium and there is an influx of products. As the reaction returns to equilibrium, the reverse reaction will occur more because there is more products. When Q < K, the chemical reaction is not in equilibrium and there is an influx of reactants. In this case, the forward reaction will occur more as the reaction returns to equilibrium. I hope this helps!

Simer_Shera_2D
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Re: Q > K, Q< K

Postby Simer_Shera_2D » Sun Jan 17, 2021 6:07 pm

When Q>K, that means that the amount of product is greater than should be at equilibrium so the reaction will shift towards the reactants. When Q<K, the amount of reactants is greater than it should be at equilibrium so the reaction will shift towards the products to reach equilibrium.

Abhinav Behl 3G
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Re: Q > K, Q< K

Postby Abhinav Behl 3G » Sun Jan 17, 2021 6:36 pm

When Q > K, that means that the products are being produced more than they would if the reaction were at equilibrium. In this case, the reaction would want to make more reactants to compensate, thus causing the reaction to favor the reactants (shift to the left).
When Q < K, that means that the products are not being produced as much as it would if the reaction were at equilibrium. In this case, the reaction would want to make more products, thus causing the reaction to favor the products (shift to the right).

Dylan_Nguyen_2C
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Re: Q > K, Q< K

Postby Dylan_Nguyen_2C » Sun Jan 17, 2021 6:52 pm

I don't know if this is super useful, but a tip that might helps some remember is when comparing Q and K, write the value of Q first and compare it to K. Then, look at opposite direction the inequality sign is facing to determine the direction that the equilibrium will shift. So for Q<K, the inequality sign's "point" is facing left, and the equilibrium will shift right(towards products) as a result. For Q>K, the inequality is pointing right, so we can predict the equilibrium will shift left towards reactants. hope this can be of use to someone

Daniela Santana 2L
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Re: Q > K, Q< K

Postby Daniela Santana 2L » Sun Jan 17, 2021 7:40 pm

Hi! When Q > K, this means that the reaction shifts to the reactants or to the left (since the reactants are on the left). When Q < K the reaction shifts towards the products or to the right (since the products are on the right). I hope this helped clear up any confusion!

joshtully
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Re: Q > K, Q< K

Postby joshtully » Sun Jan 17, 2021 10:49 pm

When Q > K, the reaction shifts towards reactants, and when Q < K, the reactions shifts towards products.

Meghan Krushena 2E
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Re: Q > K, Q< K

Postby Meghan Krushena 2E » Sun Jan 17, 2021 10:51 pm

Whether Q is greater than or less than K indicates the direction of the equation. So, if Q<K the concentration of the products is less than the concentration of the reactants compared to equilibrium, so the reaction moves from R --> P, or "shifts right"! and vice versa

Daniel Hernandez 1G
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Re: Q > K, Q< K

Postby Daniel Hernandez 1G » Sun Jan 17, 2021 10:52 pm

If Q > K, then there is an imbalance where there are more products than reactants. Therefore, the reaction would favor the left (reactants) to produce more reactants and balance it out. The opposite geos for Q < K. If Q < K is true, then there are more reactants than products which will cause more products to be produced.

Ethan Laureano 3H
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Re: Q > K, Q< K

Postby Ethan Laureano 3H » Sun Jan 17, 2021 11:17 pm

Basically, if Q is greater than K, that means that there are more products for Q than K (since products are at the numerator). According to Le Chatelier's principle, when a stress is applied to a system, the system works to counteract it. In this case, when there are more products, then the reaction will make more reactants. Looking at this mathematically, if you want to make a fraction the same value, you increase or decrease both the denominator and numerator (ex. 8/2=4 or 4/1=4). Same hold true for Q<K.

Hasan Mirza 3F
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Re: Q > K, Q< K

Postby Hasan Mirza 3F » Sun Jan 17, 2021 11:19 pm

Q>K means the reaction will move towards the products. Q<K means the reaction will shift toward the products.

Caelin Brenninkmeijer 1G
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Re: Q > K, Q< K

Postby Caelin Brenninkmeijer 1G » Sun Jan 17, 2021 11:42 pm

When Q<K, there's not enough products and when Q>K, there's too few reactants. This means that Q<K would shift towards the right and Q>K would shift towards the left.


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