Q and K

[Bianca Barcelo 4I]

When comparing Q and K, what does that exactly tell us?

[Diviya Khullar 1G]

Q is the reaction quotient and K is the equilibrium. Q basically tells us the ratio of the concentration or partial pressure of the products to that of the reactants when the reaction is not at equilibrium, while K tells the same thing when the reaction is at equilibrium. Comparing the two not only tells us whether or not the reaction is at equilibrium but can also tell us what direction the reaction will proceed in to reach equilibrium if it is not already at equilibrium. If QK then the reverse reaction will be favored. If QK then the forward reaction will be favored.

[Celeste 1I]

K tells us the equilibrium constant and Q is the ratio of the concentration of products and reactants at any given time. You can use K to find whether a reaction is in equilibrium and which side it it more likely to favor. If Q is less than K then the reaction will shift right and if Q is greater then K it will shift to the right.

[Jonathan Pai 2I]

K uses only equilibrium concentrations. Q can use any concentration at any time, which tells us where the reaction will go.

[Mercan Bayazit 4E]

K is the equilibrium constant so the reaction needs to be at equilibrium in order for us to calculate K. Q, on the other hand, can be calculated at any time during the reaction and there does not need to be an equilibrium.

[Carine Tamamian 2B]

If Q < K, then [R] > [P] and forward reaction is favored
If Q > K, then [R] < [P] and reverse reaction is favored
Q=K then reaction is at equilibrium

[Carlos De La Torre 2L]

Q and K are very similar, at equilibrium Q = K but any other time than that Q won't equal K but it will tell us which side will be favored in order to get to K.

[Jason Ye 2I]

Q is like a hypothetical reaction and K is an established equilibrium constant

[Rehan Chinoy 1K]

The value Q is useful because in comparison to a K value for a reaction it tells us whether products or reactants are favored (which direction the reaction will go towards)

[Ricardo Martin 1J]

If Q > K then a reverse reaction is favored.
If Q < K then a forward reaction is favored.

[Brian Chang 2H]

Q is the reaction quotient which can be at any time.
K is the equilibrium constant (only at equilibrium, duh.)
If Q > K then the reverse reaction is favoured.
If Q < K then the forward reaction is favoured.

Basically, it tells us which direction the reaction sits.