Difference between Q and K

[805594676]

What is the difference between Q and K? When I calculate values for each variable, they are different numbers but the formula is the same. What distinguishes the two concepts?

[Trisha Badjatia 2L]

K refers to the equilibrium constant, or the ratio of the products and the reactants at equilibrium, while Q refers to the reaction quotient. Q refers to where the reaction is at, and it's compared to K to see which way the reaction will shift. If Q > K, then the reaction will shift to the left, toward the reactants. If Q < K, then the reaction will shift to the right, toward the products.

[Sohan Talluri 1L]

The main difference between Q and K is that the reaction quotient Q can be calculated at any time during the reaction, while the equilibrium constant K can only be calculated at equilibrium. Because of this, Q has changing values as a reaction progresses and describes the current state of the reaction, while K is constant and only changes if the temperature that the reaction occurs at is changed.

Hopefully this helps and please correct me if there are any mistakes.

[Savannah Licciardello 2C]

Both Q and K are representations of the ratio of P/R. K is for when the reaction is at equilibrium. It is a constant for that reaction at a specific temperature when at equilibrium. Q is when the reaction is not at equilibrium and can change. Both are calculated the same way with P/R.

[amreen_sandhu1k]

Q is the measure of the concentrations at any point of the reaction. Whereas, K is the measure of the concentrations of the reaction at equilibrium only.

[105778693]

Q is the measure of the concentrations of products over reactions at any point of the reaction, whether it is at equilibrium or not, which means the numerical value changes according to the given scenario. K is the measure of the cocnentrations of the reaction at equilibrium only and is a constant.

[Anish_Marripati_2F]

Q represents the relative ratio of product to reactant at any time during the reaction. K is the relative ratio of product over reactant only when the chemical reaction reaches its equilibrium. Both Q and K are derived the same way. K value is useful in calculating the concentration of reactants and products for certain reactions. If you know both K and Q, you can determine whether the reaction is shifting forward or backward.

[Skylar Lo 2C]

Q would be solved for while K would be given. That way you can compare the two values and see where the reaction will shift towards.

[Kayla Ziebell 1H]

K is the equilibrium constant. Q can be calculated whenever and K is used sort of as a basis for comparison to see how the reaction has changed when comparing Q to K.

[Daniel Li 3C]

Usually, when given a problem that requires you to calculate Q, you are using it to compare to K. Q and K are calculated the same way, but Q is using initial values and K is the value of the equilibrium constant at equilibrium.

[Celine_Nguyen_3K]

K refers to the equilibrium constant of the reaction, whereas Q refers to the quotient of the reaction whenever it is not at equilibrium. That is, K can only be computed using the concentrations of the given compounds at equilibrium, when there is zero net change in reactant usage and product formation because the rates at which they occur are equal. Q can be computed using any other concentrations besides the ones at equilibrium, so it can be computed at any time during the reaction besides equilibrium, since doing so would give you K. The formulas are the same because they technically mean the same thing, just at different times (equilibrium vs. non-equilibrium) when the concentrations are different (so the inputs into the formula must be different).

[Benjamin Nguyen 1J]

K is calculated when the reaction is at equilibrium, while Q can be calculated at any time during the reaction. You can use the value of Q compared to K to determine which way the reaction will proceed to reach equilibrium.

[Aashna Bhandari 1L]

They have the same equation, but represent different ratios because Q is calculated at any time during the reaction, whereas K (the equilibrium constant) is only calculated at equilibrium. Comparing Q and K can tell us which way the reaction is progressing, and if Q=K then we know the reaction is at equilibrium.

[BriannaDis2C]

K represents the measure of concentrations of the reaction only at equilibrium whereas Q is the measure of the concentrations at any point of the reaction.

[Brenda Tran 3C]

Q is the quotient constant, while K is the equilibrium constant. Knowing this, we would use K when the reaction has come to equilibrium or when reactants and products are forming each other at a constant rate. You would use quotient constant if the reaction is not in equilibrium yet. An example that Dr. Lavelle mentioned was that if you need to go on your lunch break but your reaction is not in equilibrium at the moment, you can calculate Q.

[Rebekah Jung 1C]

Q is the concentration of products over reactants at any point other than when the reaction is at equilibrium. K is the ratio of the concentration of products over reactants at equilibrium. The relationship between Q and K is used to predict where the reaction will favor in order to achieve equilibrium.

[Thailer Phorn 1C]

Q is the measure of the concentrations of reactants and products at any point during the reaction, while K is the measure of the concentrations at equilibrium.

[Amanda Pineda 3H]

K is the equilibrium constant of a reaction which is constant (unless the temperature changes). Q is the reaction quotient at a given time in the reaction. As the reaction proceeds, Q will approach K and eventually be reached and equilibrium will be present.

[Jiayi_Cao_3E]

Hi!

Essentially, K expresses the equilibrium constant, which is the ration of products to reactants strictly when the system is at equilibrium. On the other hand, Q could be any ratio other than the ratio at equilibrium.

When the system is not at equilibrium, the value you calculate will be Q, but depending on the value of Q, the system either shifts left or right toward the K value.

[Holly Do 2J]

The difference between the Q and K value is that K is a constant, meaning it does not change and is a set number for the reaction (it does change with temperature) while on the other hand Q is a value of the ratio of products and reactants NOT at equilibrium.

[trevina_brown_2A]

Q is the measure of the concentrations at any point of the reaction, K is the measure of the concentrations of the reaction at equilibrium only.

[Madison Nguyen 3L]

K is the constant at which the reaction is at an equilibrium, meaning the ratio of products to reactant concentrations remain constant/are the same and are reacting at a constant rate. Q is at any point in the reaction when it is not at equilibrium, and when relative to the equilibrium constant, the reaction will move left or right.

[Hannah Thornton 1F]

K is the measure of the concentrations of the reaction at equilibrium, while Q is the measure of the concentrations at any point in the reaction.

[Talia Tam 3L]

K is the ratio of reactants and constants at equilibrium, while Q is the ratio at any point in the reaction.