## Reaction quotient

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

### Reaction quotient

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

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
Posts: 101
Joined: Thu Jul 25, 2019 12:17 am

### Re: Reaction quotient

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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Joined: Sat Aug 17, 2019 12:16 am
Been upvoted: 1 time

### Re: Reaction quotient

^^^ 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
Posts: 103
Joined: Thu Jul 25, 2019 12:15 am
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### Re: Reaction quotient

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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Joined: Fri Aug 30, 2019 12:17 am
Been upvoted: 1 time

### Re: Reaction quotient

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

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
Posts: 46
Joined: Wed Sep 18, 2019 12:17 am

### Re: Reaction quotient

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

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