## Q and direction

Alfred Barrion 2H
Posts: 100
Joined: Sat Jul 20, 2019 12:16 am

### Q and direction

How does Q let us predict the direction that an equilibrium practice will go through?

JohnWalkiewicz2J
Posts: 103
Joined: Thu Jul 11, 2019 12:17 am
Been upvoted: 1 time

### Re: Q and direction

Typically if Q<K, then the reaction will proceed from left to right (reactants→products)
If Q>K, then the reaction will proceed from right to left (reactants←products)

Julie Park 1G
Posts: 100
Joined: Thu Jul 25, 2019 12:15 am

### Re: Q and direction

K describes the equilibrium constant (the ratio of products and reactants at equilibrium). By comparing Q (the ratio of products and reactants at a specific instant, not necessarily at equilibrium) with K, you can tell which way the reaction will proceed to get closer to equilibrium.
For example, when Q<K, the reaction will shift right. Here, the ratio of prod/react at that particular instant is smaller than K. By looking at the relationship between the numerator(prod) and denominator(react), this means that the amount of product present is smaller (than at K). Therefore, the reaction will "go to the right" to increase the amount of product and achieve a Q that is closer to K.

Julie_Reyes1B
Posts: 105
Joined: Sat Jul 20, 2019 12:16 am

### Re: Q and direction

To add on to John, my high school chemistry teacher gave us a good way to remember which way the reaction will go. If you write K and Q in alphabetical order, then the less-than and greater-than symbols will point in the direction of the reaction. For example K>Q looks like it is pointing to the right, telling you that the reaction will tend towards products.

Posts: 97
Joined: Tue Feb 12, 2019 12:15 am

### Re: Q and direction

When Q < K at the same time during the reaction then R > P and the forward reaction is favored
When Q > K at the the same time during the reaction , then P > R and reverse reaction is favored.
When Q = K at the same time during the reaction then it is at equilibrium.