Does K change or not?

[OishiBhattacharya2K]

I am a bit confused about the behavior of the value K when reactant/product is being added/taken away in a rxn. In #10 of the Chemical Equilibria Achieve hw, the solution states that adding extra product will not affect the rate constant Kc. However on question #8, one of the correct answers state "Q>K because K decreased." So for #10, it says that K does not change, but in #8 it decreases, which seems contradictory to me. Is it because #8 involved a change in temperature? Can somebody clarify?

[Holly Do 2J]

Hi,

So the difference between question #8 and question #10 is that question #8 is a change in temperature which DOES change the Ka value while in #10 adding/removing products or reactants DOES NOT change the Ka.

I hope this cleared things up a bit.

[Barbara Soliman 1G]

K only changes with temperature. The equilibrium constant is a fixed ratio at each temperature. So if the temperature is the same, the equilibrium constant will not change at all. However, if the temperature changes, there is now a new equilibrium constant set for the temperature. Hope this helps!

[Jessica Servoss 1H]

The one major thing that can cause K to change in a reaction, is the temperature of the system. Once the temperature changes, a new K is created from the reaction.

[HaleyC 2F]

Changing the temperature changes the K value.

[Caden Ciraulo 1J]

As stated, K only changes if the temperature changes. This is the condition that is referenced when stating that the reaction occurs under the same conditions. The way this works is that K is an equilibrium constant that is constant as long as the condition of temperature is kept the same. Any other condition that is changed may temporarily shift the reaction in order to reach K again (for example, changing the concentration of reactants via adding more or decreasing the volume), but when temperature is changed, K shifts and the reaction shifts with it.

[Madison Kiggins 1E]

Hi, a change in temperature is the only thing that will change the value of K. For number 8, the thing that is changed in the system is the temperature, this results in a new K value. For number 10 on the other hand, the amount of products or reactants is what is changed and that does not result in the K value changing.

[Olivia Peony Dis 2A]

Hi!

K is constant for a given temperature, so when the temperature changes, K changes. But as long as temp does not change, K does not change.

Olivia Peony Dis 2A

[Samantha Quevedo 2L]

Kc is a constant that only changes when temperature changes. Changing the concentration of a product or reactant does not change Kc!

[tim_villasenor 1k]

are there certain cases when pressure changes Kc ?

[Caden Ciraulo 1J]

are there certain cases when pressure changes Kc ?

Changing pressure on its own won't affect K_c. However, you must be aware of why pressure changed. Knowing that PV=nRT, you there is a possibility that pressure increases as a result of temperature increasing, meaning that in a case where pressure changes due to a change in temperature, K_c also changes, but that is still due to a temperature change.

[indigoaustin 3H]

K is specific to a reaction at a specific temperature, so changing the temperature changes K. I hope this helps!

[Mahli Martinez 2I]

The only factor that really changes K would be temperature, as K remains constant so long as temperature is constant.

[LukeYing_3H]

The K value is a constant for a reaction at a specific temperature so changing the temperature will change the K value.

[Madison Yee 2B]

Adding reactant or product will not change the value of K. While the concentrations of the reactants and products will change, since K is a ratio of the concentration of products to reactants, it will not change. K really only changes when you change the temperature.

[isabella garcia - 1G]

A change in temperature will result in a change in K, which is why #8 states that Q>K because K decreased following a change in temperature.

[405509920]

It's easier to remember what changes K rather than what doesn't. ONLY temperature changes K, everything else is pretty much moot.

[Clarissa Le 1I]

For #8, K changes because the temperature changed. However, K is a constant and it can be assumed that when the temperature doesn't change, K stays the same, like in #10!

[Saebean Yi 3E]

Yes, Kc will not change no matter how much reactant or product you add; its a constant. Perhaps you're confusing it with the idea of Q, the reaction quotient, since that will change. Though, Q will naturally equal K (meaning it's at equilibrium) as the reaction shifts toward the direction in favor of the side that is lacking.
However, temperature will change the K value since K, while it is a constant, its a constant at a given temperature.

[Angela Harrington 2L]

Q changes when you add or remove reactants/products, but K does not. However, K does change when there is a temperature change.

[taline krumian 1L]

In question 8, the K value changes due to temperature change. If a reaction is exothermic, increasing temperature decreases K. If a reaction is endothermic, increasing temperature increases K.

[Rishab_Haldar_3B]

Temperature will affect the K value as the K value is constant for a reaction at a specific temperature

[Mario Prado 1K]

Hello,

The reason K can change in #8 is because that is a change in temperature which does affect K. While in #10 you are only adding/removing products which has no effect on K.

Hope this helps.

[IA_1D]

HI,
The short answer will be that K changes with temperature, not by adding or removing reactants/products.

[Albert 1I]

K changes with temperature depending on the reaction. It stays the same at a specific and constant temperature.

[Jessica Berejikian]

According to Le Chatelier's principle, K only changes if there is a change in temperature; K remains the same if there is a change in concentration in the products/reactants or a change in pressure.

[Katherine Li 1A]

K only changes when the temperature is changed. When products and/or reactants are being added or removed, K remains the same, and it is instead Q that changes, causing the reaction to shift.

[Mara Crooks 1F]

K changes with the temperature only so that is why it is affected in one problem(#8) and not the other (#10). It does not change based on the reactants or products, just temp.

[Charlie Sjogren-Black]

K changes when temperature changes.

[Sarah Hong 2K]

Changing temperature (like in #8) changes the K value, however changing concentrations (like in #10) does not permanently change the K value.

[Lindsey Walter 3E]

K is constant as long as the temperature is constant. Once tempurature changes, K will change.

[Nicole Ton 3C]

Hi! K is dependent on temperature, so when temperature changes, so does the K value. However, adding or taking away a reactant or product will not change the K value. It will cause the system to go out of equilibrium, meaning there will be a Q value, but eventually it will go back to equilibrium with the same K value.

[Reece Fong 2k]

When temperature changes, so does K. However, when concentrations change, K will remain the same and the concentrations will work to reach the same ratio as before, which is equal to K

[Nicole Friday 1E]

K only changes when there is a temperature change. K will not change with a change in the concentration, but the system will try to return back to equilibrium to return to the same K ratio from the beginning.

[Madeline Ellmore 2C]

K only changes when there is a temperature change! In terms of pressure and concentration, the ratio is staying the same between the products and reactants

[Gianna Greco 1G]

Hi! K changes if temperature changes because the equilibrium constant is fixed at a specific temperature but shifts as temperature changes.

[hanniaghernandez]

Hello! To my understanding K changes only when the temperature does. Professor Lavelle goes other this concept on the recorded lecture from Friday 1/7 if you would like to go back and watch it, he goes over the fact that the change of concentration and pressure does not change the K value but tempature does.

[Emmaplant1c]

K is the equilibrium constant at a given temperature, so will change with temperature changes!

[alexjung1A]

K only changes when temperature changes, but otherwise it will remain constant.

[Genelle Marcelino-Searles 2G]

The only thing that can change the K value is temperature, so when adding products, K does not change.

[Acharya Ranawat 3E]

K only changes due to temperature. Nothing else effects it. Hope this helps!

[Daniel Tabibian 3K]

Removing or adding products and reactants won't change the K value. The main thing that will would be temperature.

[Darren Apostol 2L]

K changes with the temperature, with each temperature having a constant K associated with it for a given reaction.

[Ruirui Lan]

Hi! K changes in response to a change in temperature but not to a change in reactant/product concentration. Since in question 8 the temperature is changed, K should also be different after the change in temp. However, in question 10, the temperature remains constant. Therefore, K should remain the same. Hope this clarifies things.