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### Reaction Quotient

Posted: Wed Jan 09, 2019 8:57 am
As I was completing the reading section, I noticed that there was a "reaction quotient" - what is the difference between this sand the K value?

### Re: Reaction Quotient

Posted: Wed Jan 09, 2019 10:08 am
K is used to describe a reaction at equilibrium. The reaction quotient is used to describe a reaction that is not at equilibrium. If the reaction quotient is equal to K, you know that the reaction is at equilibrium.

### Re: Reaction Quotient

Posted: Wed Jan 09, 2019 10:21 am
The reaction quotient still has the same formula as the equilibirum constant, except for the equilibrium constant the values used are the ones at equilibrium.

### Re: Reaction Quotient

Posted: Wed Jan 09, 2019 2:20 pm
K refers to the [P]/[R] ratio at equilibrium. Although Q also refers to the [P]/[R] ratio, it can be measured at any point in time in a reaction--including equilibrium.
If Q<K, then the forward reaction (products forming) is favored.
If Q>K, then the reverse reaction (reactants forming) is favored.
If Q=K, then the reaction is at equilibrium and reactants and products are being formed at equal rates.

### Re: Reaction Quotient

Posted: Wed Jan 09, 2019 8:24 pm
Going off of the previous comments, Q is the reaction quotient which is calculated the same way that K is. However, K is used once the reaction has reached equilibrium while Q is used for any other point in the reaction while it is reaching equilibrium.

### Re: Reaction Quotient

Posted: Thu Jan 10, 2019 11:29 am
Both K and Q represent the ratio of products to reactants, but using Q implies that the reaction is not at equilibrium and the ratio will shift until equilibrium is reached. At this point, the ratio is represented as K