K vs Q  [ENDORSED]

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Karyn Nguyen 1K
Posts: 72
Joined: Fri Apr 06, 2018 11:04 am

K vs Q

Postby Karyn Nguyen 1K » Thu Jan 10, 2019 7:23 pm

What's the difference between the formula for the equilibrium constant K and the formula for the reaction quotient Q?

ariana_apopei1K
Posts: 89
Joined: Fri Sep 28, 2018 12:27 am
Been upvoted: 1 time

Re: K vs Q

Postby ariana_apopei1K » Thu Jan 10, 2019 7:48 pm

Q changes as a reaction occurs, and K is when said reaction reaches equilibrium. If the reaction does't reach equilibrium, you can't use K, only Q

Chloe Likwong 2K
Posts: 70
Joined: Fri Sep 28, 2018 12:23 am

Re: K vs Q  [ENDORSED]

Postby Chloe Likwong 2K » Thu Jan 10, 2019 7:49 pm

The formula is the same. What's different between the two is the concept behind it. The equilibrium constant K is the ratio at equilibrium; it describes a reaction that is at equilibrium. On the other hand, the reaction quotient pertains to the ratio at any given time of the reaction.

This might elucidate the topic further: viewtopic.php?f=50&t=24065

Matthew Tran 1H
Posts: 165
Joined: Fri Sep 28, 2018 12:16 am

Re: K vs Q

Postby Matthew Tran 1H » Thu Jan 10, 2019 7:50 pm

The formula for K and Q is the same; the difference is that the numbers you plug in for K must be the equilibrium partial pressures or concentrations while for Q you can plug in the partial pressures or concentrations at any point in the reaction, not just at equilibrium.

Aleeque Marselian 1A
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Joined: Fri Sep 28, 2018 12:24 am

Re: K vs Q

Postby Aleeque Marselian 1A » Thu Jan 10, 2019 8:47 pm

The formula to find K and Q are the same. However, K is the ratio of at equilibrium and therefore includes the values of the reaction at equilibrium. Meanwhile, Q is the reaction quotient and is the ratio at any given time in the reaction.

vaishali 1D
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Joined: Fri Sep 28, 2018 12:19 am

Re: K vs Q

Postby vaishali 1D » Sun Jan 13, 2019 11:39 am

The formula is the same, but K is the ratio at equilibrium, whereas Q is the reaction quotient. The numbers you plug in decide whether you're using K or Q.

Jchellis 1I
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Joined: Fri Sep 28, 2018 12:15 am

Re: K vs Q

Postby Jchellis 1I » Sun Jan 13, 2019 8:43 pm

So can there be only one value for K but multiple values for Q as the reaction progresses?

allisoncarr1i
Posts: 60
Joined: Fri Sep 28, 2018 12:15 am

Re: K vs Q

Postby allisoncarr1i » Sun Jan 13, 2019 8:49 pm

The partial pressures and concentrations do not have to be at equilibrium for Q but they do for K. Other than that, it's the same equation.


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