All High School Chemistry Resources
Example Questions
Example Question #1 : Help With Reaction Quotient
Consider the following balanced reaction:
The solution has the following concentrations:
Based on these concentrations, what will happen to the solution?
It will shift to the right
More information is needed in order to answer the question
The system is at equilibrium
It will shift to the left
It will shift to the left
By placing these initial concentrations in the equilibrium expression, we can compare the reaction quotient, , to the equilibrium constant, .
The reaction quotient for this reaction is:
Note that the reactant is a pure solid, and will not be included in this expression. By setting this equal to the equilibrium constant, we can see whether or is larger in value.
We can predict how a solution will change based on the value of . When is less than , the reaction will shift to the right. If is greater than , the reaction will shift to the left. If is equal to , the solution is at equilibrium.
Since the value for is greater than the equilibrium constant in this instance, the reaction will shift to the left.
Example Question #52 : Reactions And Equilibrium
Consider the following reaction.
What is the reaction quotient if ?
There is not enough information to answer this question
The reaction quotient, or Q, of the above reaction is equal to the products over the reactants. Q is calculated in the same manner as Keq, but does not require that the reaction be at equilibrium.