Print this list and try working these problems before checking your answers and looking at the hints.

Simple Problems

• III-4(1). What are the equilibrium partial pressures of N₂O₄ and NO₂ when 1.000 atm of N₂O₄ is introduced into a 500.0 mL container at room temperature?
  Unbalanced reaction: N₂O_{4 (g)} NO_{2 (g)}     K_eq = 0.144 at 25^oC.

• III-4(2). What is the equilibrium constant, K_eq, for the reaction below if the following partial pressures were measured at equilibrium: P_SO2 = 0.55 atm, P_O2 = 0.30 atm, and P_SO3 = 0.15 atm.
  Unbalanced reaction: SO_{2 (g)} + O_{2 (g)} SO_{3 (g)}.

• III-4(3). What are the equilibrium partial pressures of all gases when 1.00 atm of H₂O_(g) is heated with coke to 900 K?
  Unbalanced reaction: C_(s) + H₂O_(g) CO_(g) + H_{2 (g)}     K_eq = 0.45 at 900 K.

Advanced Problems

• III-5(1). What are the equilibrium partial pressures of N₂O₄ and NO₂ when 0.20 mol of N₂O₄ and 0.80 mol of NO₂ are sealed in a 2.00 L container and placed on a steam bath?     K_eq = 11 at 100^oC.
  Unbalanced reaction: N₂O_{4 (g)} NO_{2 (g)}     K_eq = 11 at 100^oC.

• III-5(2). What is the equilibrium partial pressure of carbon dioxide when 50.0 g of calcium carbonate is heated to 900^oC in a 100.0 mL flask that was sealed and evacuated before heating.
  Unbalanced reaction: CaCO_{3 (s)} CaO_(s) + CO_{2 (g)}     K_eq = 1.04 atm at 900^oC.

• III-5(3). In problem III-3(3), you found the equilibrium partial pressures when 1.00 atm of H₂O_(g) is heated with coke to 900 K. The equilibrium partial pressures were:
  P_H2O = 0.52 atm       P_CO = 0.48 atm       P_H2 = 0.48 atm
  What are the new equilibrium partial pressures of all gases if the volume containing this equilibrium mixture is increased by a factor of 4?
  Unbalanced reaction: C_(s) + H₂O_(g) CO_(g) + H_{2 (g)}     K_eq = 0.45 at 900 K.