Reversible reactions

Definition

Reversible reactions are chemical reactions where the reactants form products that can react together to reform the reactants. These reactions can proceed in both forward and reverse directions.

5 Must Know Facts For Your Next Test

1. In a reversible reaction, the system reaches a state of dynamic equilibrium where the rate of the forward reaction equals the rate of the backward reaction.
2. The position of equilibrium can be shifted by changing conditions such as temperature, pressure, and concentration according to Le Chatelier's Principle.
3. The equilibrium constant ($K_{eq}$) is a ratio of the concentrations of products to reactants at equilibrium for a given temperature.
4. A large $K_{eq}$ value indicates that products are favored at equilibrium, while a small $K_{eq}$ value indicates that reactants are favored.
5. Catalysts do not affect the position of equilibrium; they only speed up the rate at which equilibrium is achieved.

Review Questions

• What happens to a reversible reaction when it reaches dynamic equilibrium?
• How does changing temperature affect the position of equilibrium in an exothermic reversible reaction?
• What does the value of $K_{eq}$ signify in terms of product and reactant concentrations?

Related terms

Dynamic Equilibrium: A state in which the forward and reverse reactions occur at equal rates, resulting in no net change in concentration of reactants and products.

$K_{eq}$ (Equilibrium Constant): A numerical value that expresses the ratio of concentrations of products to reactants at equilibrium for a particular reaction at a specific temperature.

Le Chatelier's Principle: A principle stating that if an external change is applied to a system at equilibrium, the system adjusts itself to partially counteract the applied change.