Q and K

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marcus lin 1E
Posts: 54
Joined: Fri Sep 28, 2018 12:28 am

Q and K

Postby marcus lin 1E » Sun Jan 13, 2019 7:49 pm

How are Q and K related?

arif_latif_2G
Posts: 60
Joined: Fri Sep 28, 2018 12:23 am

Re: Q and K

Postby arif_latif_2G » Sun Jan 13, 2019 7:55 pm

Both are the reaction quotient, but K is when the reaction is at equilibrium, while Q can represent the reaction quotient at any given moment. If Q is lower than K, then the forward reaction is favored. Similarly, if Q is greater than K, then the reverse reaction is favored.

sarahtang4B
Posts: 132
Joined: Fri Sep 28, 2018 12:27 am

Re: Q and K

Postby sarahtang4B » Sun Jan 13, 2019 7:58 pm

They are both the reactant quotients but Q tells you if a reaction will shift forward or backward and K represents equilibrium

Srikar_Ramshetty 1K
Posts: 64
Joined: Fri Sep 28, 2018 12:27 am

Re: Q and K

Postby Srikar_Ramshetty 1K » Sun Jan 13, 2019 7:59 pm

K is an equilibrium constant at a certain temperature. This represents the ratio between [products] and [reactants] at equilibrium. Q represents the ratio between [products] and [reactants] at any point within the reaction. Therefore, Q=K at equilibrium since the two ratios will be equivalent. If Q is larger than K (Q>K) that would indicate that there is more products in the system than what is seen at equilibrium and would indicate that the reaction would favor the formation of reactants. If Q is smaller than K (Q<K) that would indicate that there are more reactants in the system than at equilibrium, and the system would favor the formation of products.

Hope that helps!

Jaqueline Monreal 2L
Posts: 57
Joined: Fri Sep 28, 2018 12:28 am

Re: Q and K

Postby Jaqueline Monreal 2L » Sun Jan 13, 2019 8:26 pm

Q: gives the reaction quotient at any moment
K: gives the reaction quotient at equilibrium
Q<K : forward reaction favored
Q>K : reverse reaction favored

Eva Zhao 4I
Posts: 101
Joined: Sun Sep 29, 2019 12:16 am

Re: Q and K

Postby Eva Zhao 4I » Tue Jan 21, 2020 10:32 am

Q and K are calculated essentially the same way. However, Q expresses the relative ratio of products to reactants at a given instant not necessarily at equilibrium, which is why you can compare Q and K to determine the direction of a reaction. The reaction shifts right if Q<K, shifts left if Q>K, and is at equilibrium if Q=K.

Kaylee Clarke 1G
Posts: 103
Joined: Fri Aug 30, 2019 12:15 am

Re: Q and K

Postby Kaylee Clarke 1G » Tue Jan 21, 2020 11:40 am

K is the reaction at equilibrium. Q is the reaction at any point. K greater than Q is a forward reaction. Q greater than K is a reverse reaction.

205291012
Posts: 50
Joined: Mon Nov 11, 2019 12:17 am

Re: Q and K

Postby 205291012 » Tue Jan 21, 2020 11:20 pm

Q and K both measure the ratio of the concentration of products to concentration of reactants. However, K is a constant and it is the value you get when the mixture is at equilibrium. Q is the same ratio but it is measured at any point during the reaction so it can be compared to K to figure out whether the reaction will favor formation of products or reactants.

Joanne Lee 1J
Posts: 100
Joined: Thu Jul 25, 2019 12:15 am

Re: Q and K

Postby Joanne Lee 1J » Wed Jan 22, 2020 11:22 pm

K is used when the reaction is at equilibrium but Q is used at anytime during the experiment. Oftentimes, the Q and K values can be compared to see whether the reaction favors the reactant or the products.


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