Written by the Fiveable Content Team โข Last updated September 2025
Written by the Fiveable Content Team โข Last updated September 2025
Definition
Equilibrium in chemistry occurs when the rates of the forward and reverse reactions are equal, resulting in no net change in the concentration of reactants and products. This state can be reached in both closed systems and dynamic processes.
5 Must Know Facts For Your Next Test
At equilibrium, the concentrations of reactants and products remain constant over time.
The equilibrium constant ($K_{eq}$) expresses the ratio of product concentrations to reactant concentrations at equilibrium.
Le Chatelier's Principle states that if a system at equilibrium is disturbed, it will shift to counteract the disturbance and re-establish equilibrium.
A large $K_{eq}$ value indicates that products are favored at equilibrium, whereas a small $K_{eq}$ value indicates that reactants are favored.
Changes in temperature can affect the position of the equilibrium by changing the value of $K_{eq}$.
Review Questions
Related terms
$K_{eq}$: The equilibrium constant, a number that expresses the ratio of product concentrations to reactant concentrations at equilibrium for a given reaction.
A principle stating that if an external change is applied to a system at equilibrium, the system adjusts in such a way as to counteract that change and restore a new equilibrium.