Q vs K  [ENDORSED]

Moderators: Chem_Mod, Chem_Admin

hannahdaijo_4H
Posts: 48
Joined: Fri Sep 28, 2018 12:27 am

Q vs K

Postby hannahdaijo_4H » Wed Jan 16, 2019 8:47 pm

What exactly is the difference between the reaction quotient and the equilibrium constant?

Grace Kim 1J
Posts: 60
Joined: Fri Sep 28, 2018 12:18 am
Been upvoted: 1 time

Re: Q vs K

Postby Grace Kim 1J » Wed Jan 16, 2019 8:52 pm

K is the constant of a certain reaction when it is in equilibrium, while Q is the quotient of activities of products and reactants at any stage of a reaction. The direction of a reaction can be determined by comparing Q and K.

The difference is that equilibrium constant (K) is the ratio between the concentrations of products and the concentrations of reactants at equilibrium.

Courtney Quan 1C
Posts: 60
Joined: Fri Sep 28, 2018 12:26 am
Been upvoted: 2 times

Re: Q vs K

Postby Courtney Quan 1C » Thu Jan 17, 2019 11:33 am

As mentioned above, K as the equilibrium constant is calculated when the reaction is in equilibrium. Q, the reaction quotient, is found when the reaction is at any point other than equilibrium- in other words, when the reaction is not at equilibrium. While K and Q are calculated the same way ([P]/[R]), comparing the two values is helpful in indicating which direction a reaction will proceed. For instance, when Q > K, more products/insufficient reactants are present at that instance than during equilibrium, so the reaction will proceed towards the left to make more reactants.

yuetao4k
Posts: 60
Joined: Fri Sep 28, 2018 12:27 am
Been upvoted: 1 time

Re: Q vs K  [ENDORSED]

Postby yuetao4k » Thu Jan 17, 2019 1:15 pm

Q can be calculated at any given point of the reaction. K is calculated when the system is in equilibrium.

Jasmine Chow 1F
Posts: 60
Joined: Fri Sep 28, 2018 12:16 am
Been upvoted: 1 time

Re: Q vs K

Postby Jasmine Chow 1F » Thu Jan 17, 2019 1:22 pm

The Q is the same thing as the K value however it is the constant when the reaction is not in equilibrium. So you often compare K and Q to see which side of the reaction is favored when it is not in equilibrium.


Return to “Equilibrium Constants & Calculating Concentrations”

Who is online

Users browsing this forum: No registered users and 1 guest