Q & K?

[Guadalupe T 1E]

I know when products/reactants are favored in terms of K>1 etc, but what are the rules when Q>K or Q<K?

[Alyssa Parry Disc 1H]

I think that was just for Chem 14A

[Daniisaacson2F]

In the problems that they are giving in the homework, they are treating Q as if it was K, and using that value to determine whether the reactants or products are favored. In other words, they usually will not give you a K value to compare it to.

[Sarkis Sislyan 1D]

If Q>K then that means there is more product than at the equilibrium concentration. As such, LeChatelier's principle tells us that the reactants will be favored. If Q<K then that means there is more reactant than at the equilibrium concentration, so the products will be favored.

[McKenna disc 1C]

If Q>K then that means there is more product than at the equilibrium concentration. As such, LeChatelier's principle tells us that the reactants will be favored. If Q<K then that means there is more reactant than at the equilibrium concentration, so the products will be favored.

Yep! Q just has to do with the concentrations of the reaction's components at any time. The equation's format is the same for Q as it is for K-- concentration of products raised to the powers of their stoichiometric coefficients divided by concentrations of reactants raised to the powers of their stoichiometric coefficients. The only difference is that Q can be measured at any time, whereas K refers only to equilibrium concentrations. And just as the reply above this explains, the direction in which the reaction will proceed depends on Q with respect to K. :) Hope this helps!