Topic Equilibrium

What effect does increasing both pressure and temperature have on the equilibrium constant, K_c?

N₂ (g) + 3H₂ (g) ⇌ 2NH₃ (g) ΔH = −45.9 kJ

• Decreases

• Increases

• Remains constant

• Cannot be predicted as effects are opposite

What will happen if the pressure is increased in the following reaction mixture at equilibrium?

CO₂ (g) + H₂O (l) ⇌ H⁺ (aq) + HCO₃⁻ (aq)

• The equilibrium will shift to the right and pH will decrease.

• The equilibrium will shift to the right and pH will increase.

• The equilibrium will shift to the left and pH will increase.

• The equilibrium will shift to the left and pH will decrease.

Consider the equilibrium between N₂O₄(g) and NO₂(g).

N₂O₄(g) ⇌ 2NO₂(g) ΔH = +58 kJmol⁻¹

Which changes shift the position of equilibrium to the right?

I. Increasing the temperature

II. Decreasing the pressure

III. Adding a catalyst

• I and II only

• I and III only

• II and III only

• I, II and III

The enthalpy change for the dissolution of NH₄NO₃ is +26 kJ mol^–1 at 25 °C. Which statement about this reaction is correct?

• The reaction is exothermic and the solubility decreases at higher temperature.

• The reaction is exothermic and the solubility increases at higher temperature.

• The reaction is endothermic and the solubility decreases at higher temperature.

• The reaction is endothermic and the solubility increases at higher temperature.

Which variable affects the equilibrium constant, K_c?

• Atmospheric pressure

• Catalyst

• Concentration of reactants

• Temperature

• A

• B

• C

• D

What happens when the temperature of the following equilibrium system is increased?

CO(g) + 2H₂(g) CH₃OH(g) ΔH^θ = -91kJ

• A

• B

• C

• D

• The amount of hydrogen gas remains the same but its concentration decreases
  

• The forward reaction is favored

• The reverse reaction is favored
  

• the value of KC remains unchanged