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### Q and K

Posted: Sat Dec 03, 2016 10:47 am
Is there an actual difference in the formulas for Q different from K?

### Re: Q and K

Posted: Sat Dec 03, 2016 11:12 am
There is no difference between the two formula.

### Re: Q and K

Posted: Tue Nov 21, 2017 4:42 pm
No difference in the formulas, just the fact that K is the constant at chemical equilibrium and Q refers to the initial concentrations of the reactants and products.

### Re: Q and K  [ENDORSED]

Posted: Tue Nov 21, 2017 5:20 pm
The two formulas are the same. You compare Q to K in order to determine which way the reaction will shift (sit). If Q<K, it will shift/sit right (toward products), if Q>K, it will shift/sit left (towards reactants).

### Re: Q and K

Posted: Fri Nov 24, 2017 9:41 pm
There is no difference between the two formulas. The molar concentrations, however, in k should be the ones at equilibrium. At Q, the molar concentrations can be at any point.

### Re: Q and K

Posted: Fri Nov 24, 2017 10:43 pm
As the others have mentioned, there is no difference in the formula, but it's important to use the right numbers. Use the concentrations/pressures provided when the system isn't at equilibrium to calculate Q.

### Re: Q and K

Posted: Fri Nov 24, 2017 11:57 pm
There are no difference between the formuals. However, Q refers to the reactants and products whereas K refers to the chemical equilibrium.

### Re: Q and K

Posted: Mon Nov 27, 2017 8:08 am
The formula of Q and K are the same, but they have different meanings.

### Re: Q and K

Posted: Fri Dec 01, 2017 5:00 pm
There is no difference between the formulas, but they calculate different things. K is calculated by using the equilibrium concentrations and Q is calculated by using the concentrations at a different time during the reaction.

### Re: Q and K

Posted: Sun Dec 03, 2017 3:43 pm
K is the equilibrium constants of the reaction, which is only changed with the temperature. However, Q is the reaction rate at any time of the reaction, which will be changed with add/remove of the substance,volume,and concentrations. In the other words, we say Q includes K; K is one value of Q in the spacial condition.

### Re: Q and K

Posted: Sun Dec 03, 2017 11:42 pm
Q is the formula for concentration of products/reactants at any time. K is the ratio of products to reactants at equilibrium and they use the same formulas

### Re: Q and K

Posted: Sun Dec 03, 2017 11:44 pm
The formulas are the exact same.

### Re: Q and K

Posted: Sun Dec 03, 2017 11:53 pm
There is no difference in the formulas themselves. It is just that K specifically refers to when the reaction is at equilibrium and Q refers to any moment of time aside from that.

### Re: Q and K

Posted: Tue Jan 08, 2019 6:13 pm
K is found using concentrations at equilibrium, BUT to calculate Q do we just use the initial concentrations or concentrations at any given time?

### Re: Q and K

Posted: Wed Jan 09, 2019 1:00 pm
No difference. It's the same but K is when equilibrium is achieved. Q is at any point of the reaction.

### Re: Q and K

Posted: Wed Jan 09, 2019 1:06 pm
the formulas are the same, K is at equillibrium

### Re: Q and K

Posted: Wed Jan 09, 2019 3:07 pm
both of the formulas for Q and K are the same!

### Re: Q and K

Posted: Thu Jan 10, 2019 12:22 pm
Virtually no difference between how we calculate Q and K, but they just tell us different things ( which - either reactant or product is in excess and which side the equilibrium sits)

### Re: Q and K

Posted: Thu Jan 10, 2019 3:14 pm
There is no difference in the way we calculate Q and K, the difference is that Q is associated with initial values and K is associated with equilibrium values.

### Re: Q and K

Posted: Thu Jan 10, 2019 3:18 pm
You can calculate Q and K the same way by following the formula [products]/[reactants] . The only difference is that the reaction quotient, Q is for ANY TIME during the reaction while the values for K are always the concentrations at equilibrium.

### Re: Q and K

Posted: Thu Jan 10, 2019 5:24 pm
No difference in the way you calculate Q and K, but there is a major difference in what they mean. Q means the ratio of Products and reactants at any given point of the reaction, but K is the ratio of Products and Reactants at equalibrium. When comparing Q and K, it can tell us which reaction rate is higher.

### Re: Q and K

Posted: Thu Jan 10, 2019 8:36 pm
Same formulas but they calculate for different things

### Re: Q and K

Posted: Fri Jan 11, 2019 9:48 am
How do you know when to use Q or K, is there a certain calculation? Or would the question specify so?

### Re: Q and K

Posted: Fri Jan 11, 2019 9:52 am
Both have the same formula, but they calculate different things.

### Re: Q and K

Posted: Fri Jan 11, 2019 12:08 pm
There is no difference in the formulas for Q and K. The main difference lies in what Q and K are calculated for. K is the equilibrium constant, therefore it can only be applied to identify when the reaction is at equilibrium. Q, on the other hand, is the reaction quotient and can be calculated at any time during the reaction. The main purpose of Q is to compare it to K and identify which direction the reaction should be proceeding in order to attain equilibrium. When Q is equal to K, then the reaction is at equilibrium.

### Re: Q and K

Posted: Fri Jan 11, 2019 12:20 pm
105085381 wrote:K is found using concentrations at equilibrium, BUT to calculate Q do we just use the initial concentrations or concentrations at any given time?

Yes. Q can be calculated at any time in the reaction, and then you would compare it to the given equilibrium constant, K, to determine if the reaction is at equilibrium, and if not, then which directional reaction is favored. Hope this helps!

### Re: Q and K

Posted: Fri Jan 11, 2019 1:07 pm
The formulas for both Q and K are the same. K specifically tells us when the reaction is at equilibrium. Q can be be found during any instance of the reaction in order to determine which direction the reaction is going when it is compared to K.

### Re: Q and K

Posted: Fri Jan 11, 2019 5:08 pm
Both Q and K use the same formula.

### Re: Q and K

Posted: Fri Jan 11, 2019 6:03 pm
K and Q are calculated in the same way.

### Re: Q and K

Posted: Fri Jan 11, 2019 7:01 pm
Q and K have the same formula, they are both the concentration of the products divided by the concentration of reactants.

### Re: Q and K

Posted: Fri Jan 11, 2019 7:34 pm
There is no difference.

### Re: Q and K

Posted: Fri Jan 11, 2019 11:56 pm
The formulae themselves have no difference, but K is only used when the chemical reaction is at equilibrium. Using the equation with Q helps you determine whether the reaction goes forward or in reverse to reach equilibrium.

### Re: Q and K

Posted: Sat Jan 12, 2019 1:14 am
nope no difference! Hope that helped because I have to sleep now!

### Re: Q and K

Posted: Sat Jan 12, 2019 1:28 am
Tony Ong 3K wrote:nope no difference! Hope that helped because I have to sleep now!

Goodnight!

### Re: Q and K

Posted: Sat Jan 12, 2019 1:33 am
Yes K and Q have the same formula. More importantly, though, they represent different things that, when compared, yield answers to the direction of the reaction at a certain point in time. K=constant (at equilibrium only), Q=constant (at any point in time throughout the reaction). Each specific value for Q and K are found using the same formula using concentration or pressure based on given variables, as you know. So, when Q<K the reaction favors the products (i.e. will produce more of them), when Q>K the reaction favors the reactants (reverse reaction occurs more often), and when Q=K you've reached or returned to equilibrium. Hope this is helpful. :)

### Re: Q and K

Posted: Sat Jan 12, 2019 2:37 pm
Since they have the same formula, it is just a view of the value of the products and reactants and using this value to see how it applies to the equilibrium constant.