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### Q and K

Posted: Sun Jan 12, 2020 5:37 pm
What is the difference between Q and K?

### Re: Q and K

Posted: Sun Jan 12, 2020 5:49 pm
K is the equilibirum constant, calculated using the formula [Products]/[Reactants] when the concentrations of both are at equilibrium. Q is calculated using the same formula, but the concentrations of both the products and reactants do not necessarily need to be at equilibirum. We use Q and K to determine if a system is at equilibirum, as when Q > K or Q < K a system is not at equilirium and a shift must occur in the reverse direction for the former case or the forward direction in the latter case for equilibirum to be re-established.

### Re: Q and K

Posted: Sun Jan 12, 2020 5:55 pm
K is a constant which doesn't change. Q is the reaction quotient, which is calculated the same as K, but the key difference is that k is calculated when the reaction is at equilibrium, while q doesn't have to be. q can be used to determine whether or not the equation will proceed forward or backward.

### Re: Q and K

Posted: Sun Jan 12, 2020 5:58 pm
K never changes since the equilibrium will always have the same ratio of reactants to products. However, Q values can change depending on how far along into a reaction you are since they are not calculated at equilibrium. Depending on if the equation is shifted to the left or the right, there can be more reactants or products than there are at equilibrium.

### Re: Q and K

Posted: Sun Jan 12, 2020 8:25 pm
K is a constant that is calculated during equilibrium, but Q is the reactant quotient that is not calculated during equilibrium. Q is a good indicator of which way a reactant will be favored; if its less than K, then the reaction is favored forwards, and vice-versa.

Posted: Sun Jan 12, 2020 11:09 pm
K is the equilibrium constant while Q is the reaction quotient.

### Re: Q and K

Posted: Sun Jan 12, 2020 11:36 pm
K = equilibrium constant, K is the same for a given reaction at a given temperature. Q = reaction quotient, it is the ratio of P/R at any given moment during a reaction.