Heterogeneous equilibrium

Definition

Heterogeneous equilibrium involves reactants and products in different phases, such as solids, liquids, and gases. The equilibrium constant expression for these systems only includes the concentrations of the gaseous and aqueous species.

5 Must Know Facts For Your Next Test

1. In heterogeneous equilibrium, pure solids and pure liquids are not included in the equilibrium constant expression.
2. The equilibrium constant for a heterogeneous reaction is denoted as $K_c$ or $K_p$, depending on concentration or partial pressure.
3. For a reaction involving gases, changes in pressure can shift the position of equilibrium according to Le Chatelier's Principle.
4. Solubility equilibria often involve heterogeneous systems where a solid dissolves to form ions in solution.
5. Temperature changes can affect the value of the equilibrium constant for heterogeneous reactions.

Review Questions

• Why are pure solids and pure liquids excluded from the equilibrium constant expression in a heterogeneous equilibrium?
• How does changing pressure influence a heterogeneous system involving gases?
• What impact does temperature have on the equilibrium constant of a heterogeneous reaction?

Related terms

Equilibrium Constant ($K$): $K$ quantifies the ratio of concentrations of products to reactants at equilibrium for a given chemical reaction.

$K_c$: $K_c$ is the equilibrium constant expressed in terms of molar concentrations of the reactants and products.

$K_p$: $K_p$ is the equilibrium constant expressed in terms of partial pressures of gaseous reactants and products.