Equilibrium Expressions Worksheet

Equilibrium Expressions

Read each question carefully and provide the best answer. Remember to show your work for calculations and clearly state equilibrium expressions.

Chemical equilibrium is a state where the rate of the forward reaction equals the rate of the reverse reaction, and the concentrations of reactants and products remain constant. The equilibrium expression, K, describes the ratio of product concentrations to reactant concentrations at equilibrium, each raised to the power of their stoichiometric coefficients.

1. Which of the following statements is TRUE regarding a system at chemical equilibrium?

2. In an equilibrium expression, pure solids and pure liquids are   from the expression.

3. The equilibrium constant, Kc, is expressed in terms of  , while Kp is expressed in terms of  .

4. Write the equilibrium expression (Kc) for the following reaction:

N₂(g) + 3H₂(g) ⇌ 2NH₃(g)

5. Write the equilibrium expression (Kc) for the following heterogeneous reaction:

CaCO₃(s) ⇌ CaO(s) + CO₂(g)

6. Write the equilibrium expression (Kp) for the following reaction:

2SO₂(g) + O₂(g) ⇌ 2SO₃(g)

7. A large value of Kc indicates that the products are favored at equilibrium.

8. The value of the equilibrium constant changes with temperature.

9. For the reaction A(g) + B(g) ⇌ C(g), at equilibrium, the concentrations are [A] = 0.50 M, [B] = 0.75 M, and [C] = 1.50 M. Calculate the equilibrium constant Kc.