Reaction quotient

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Rhea Shah 2F
Posts: 97
Joined: Thu Jul 25, 2019 12:17 am

Reaction quotient

Postby Rhea Shah 2F » Thu Jan 09, 2020 5:56 pm

I'm sure this has been asked before, but could someone explain how K and Q have different values even though the same principle is used to calculate both?

Alice Ma 2K
Posts: 52
Joined: Wed Nov 13, 2019 12:26 am

Re: Reaction quotient

Postby Alice Ma 2K » Thu Jan 09, 2020 6:00 pm

K and Q can have different values because the concentrations used the calculate them are different even though the method to do so is the same. Because Q can be calculated at any point during the reaction, the concentrations won't be constant like they would if you were calculating K.

Sartaj Bal 1J
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Re: Reaction quotient

Postby Sartaj Bal 1J » Thu Jan 09, 2020 6:09 pm

Q, the reaction quotient, is calculated at any time during the reaction when the concentrations are different than at equilibrium and is usually compared to K, the equilibrium constant, to determine which direction a reaction will proceed. In this case, K will already be known so if the calculated value does not match the K value, it will be considered Q. If Q is less than K at some point during the reaction, then there are more reactants than products and the forward reaction is favored. If Q is greater than K at some point during the reaction, then there are more products than reactants and the reverse reaction is favored.

Kassidy Ford 1I
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Re: Reaction quotient

Postby Kassidy Ford 1I » Sat Jan 11, 2020 3:29 pm

^^^ to go off what they said, if Q=K then the reaction is at equilibrium, so the concentrations would be the same as well

KHowe_1D
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Re: Reaction quotient

Postby KHowe_1D » Sat Jan 11, 2020 3:41 pm

They have different values because K is only at equilibrium and Q can be calculated at any time during the reaction.

Nikki Razal 1L
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Re: Reaction quotient

Postby Nikki Razal 1L » Sat Jan 11, 2020 3:46 pm

K is calculated at equilibrium , while Q is calculated anytime during the reaction

805394719
Posts: 104
Joined: Wed Sep 11, 2019 12:16 am

Re: Reaction quotient

Postby 805394719 » Sat Jan 11, 2020 4:04 pm

The reaction quotient is used to calculate the ratio of the reactant and product concentrations at any point as the reaction takes place. When the reaction quotient equals the equilibrium constant k, the reaction reaches equilibrium. Thus, the reaction quotient is used to calculate whether the forward or reverse reaction proceeds by looking at the concentrations of the products and reactants and comparing it to the k value. If the reaction quotient is smaller than k, the forward reaction is favored because there are more reactants than products, and if the reaction quotient is greater than k, the reverse reaction is favored since there are more products than reactants.

Andres Merlos 2L
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Joined: Wed Sep 18, 2019 12:17 am

Re: Reaction quotient

Postby Andres Merlos 2L » Sat Jan 11, 2020 4:14 pm

Q is the reaction quotient, which can be used anytime during a reaction dealing with gases. K is the equilibrium constant, so it can only be calculated once the reaction is at equilibrium.

Emily Lo 1J
Posts: 50
Joined: Thu Sep 19, 2019 12:16 am

Re: Reaction quotient

Postby Emily Lo 1J » Sun Jan 12, 2020 4:57 pm

K can only be calculated when the reaction has reached equilibrium. Q can be calculated at any point in a reaction.


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