Effect of Concentration on Equilibrium

If you were to change the CONCENTRATION, you will have disrupted the equilibrium balance, meaning the reaction is no longer in equilibrium for a short amount of time.

When this happens, the reaction RESPONDS and gets itself back into equilibrium and COUNTERACTS the change that was made to it.

You can predict the direction the equilibrium shifts for the short amount of time by knowing whether the concentration that changes is a REACTANT or PRODUCT.

Here are all the possible scenarios: