Reaction Quotient

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Harjot Manku 1C
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Reaction Quotient

Postby Harjot Manku 1C » Sun Jul 30, 2017 10:23 pm

What are the differences between Equilibrium Constant (K) and the Reaction Quotient (Q)?

Dabin Kang 1B
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Re: Reaction Quotient

Postby Dabin Kang 1B » Sun Jul 30, 2017 11:29 pm

The reaction quotient (Q) is similar to the equilibrium constant (K), but K is the constant when the reaction is in equilibrium while Q is for any stage of the reaction except when it is at equilibrium.

Wu Yuchen A1
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Re: Reaction Quotient

Postby Wu Yuchen A1 » Mon Jul 31, 2017 10:20 pm

Dabin Kang 1B wrote:The reaction quotient (Q) is similar to the equilibrium constant (K), but K is the constant when the reaction is in equilibrium while Q is for any stage of the reaction except when it is at equilibrium.

For extension the value of K can't be influenced by the concentration of reactant or production but temperature, while Q is calculated from the current concentration of reactant and production.

Krista Mercado 1B
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Re: Reaction Quotient

Postby Krista Mercado 1B » Sun Jan 20, 2019 10:57 pm

By comparing Q to K, it will tell you whether the reaction will proceed forward, backward, or is already at equilibrium
If Q = K, then the reaction is at equilibrium
If Q < K, then the reaction will favor the products (proceeds forward)
If Q > K, then the reaction will favor the reactants (proceeds backward)

Asia Yamada 2B
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Re: Reaction Quotient

Postby Asia Yamada 2B » Tue Jan 12, 2021 1:27 pm

K is the ratio of products to reactants at equilibrium. Q is the reaction quotient that is calculated at any point in time during the reaction. It is similar to K where it is the ratio of products to reactants. You can compare Q to K to determine which way the reaction will proceed to eventually establish equilibrium where Q=K.

Alexandra Ahlschlager 1L
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Re: Reaction Quotient

Postby Alexandra Ahlschlager 1L » Tue Jan 12, 2021 1:48 pm

K is the ratio of products to reactants only when the reaction is at equilibrium, while Q is the ratio of products to reactants at a random point in time. By comparing Q and K, we can find out what direction a given reaction (Q) shifts towards in order to reach equilibrium (K). For example, if Q is smaller than K, we know that there are too many reactants at that point in time, and therefore, the reaction will shift towards the right to reach equilibrium.

Norah Gidanian 3D
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Re: Reaction Quotient

Postby Norah Gidanian 3D » Tue Jan 12, 2021 3:09 pm

K is the value when the concentrations have reached equilibrium while Q is a form of the equilibrium constant expect the reaction has not yet reached equilibrium.

Nayra Gharpetian 3F
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Re: Reaction Quotient

Postby Nayra Gharpetian 3F » Tue Jan 12, 2021 5:50 pm

Q uses the concentration values we currently have, but K uses the equilibrium concentrations

Gina Spagarino 3G
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Re: Reaction Quotient

Postby Gina Spagarino 3G » Wed Jan 13, 2021 10:35 am

If you put K in front of Q in the comparison [K>Q or K<Q] the comparison sign points to the direction the reaction shifts, I double check that my logic behind which direction to shift is correct with this [ex with K>Q there must be more products at equilibrium there must be a higher concentration of products at equilibrium than there is now, so the more products must be produced and the reaction shifts to the right, where the arrow is pointing]

Sreeram Kurada 3H
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Re: Reaction Quotient

Postby Sreeram Kurada 3H » Wed Jan 13, 2021 11:04 am

The reaction quotient is basically the ratio of the products to reactants not at equilibrium (typically used when something new is added into the reaction). While the equilibrium constant is the ratio of products to reactions at equilibrium, or when the concentrations of products to reactants is constant. Also important to note, here that this ratio doesn't change, it is typically always the same unless there is a temperature change.

Charlotte Adams 1A
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Re: Reaction Quotient

Postby Charlotte Adams 1A » Wed Jan 13, 2021 11:09 am

the reaction quotient expression has the same form as expression K, but it refers to any stage of the reaction


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