The industrial synthesis of methanol from carbon monoxide and hydrogen is represented by the homogeneous equilibrium below:
CO(g)+2H2(g)⇌CH3OH(g)ΔH=−91 kJ mol−1 \text{CO}(\text{g}) + 2\text{H}_2(\text{g}) \rightleftharpoons \text{CH}_3\text{OH}(\text{g}) \quad \Delta H = -91\text{ kJ mol}^{-1} CO(g)+2H2(g)⇌CH3OH(g)ΔH=−91 kJ mol−1Which statement about this system is correct?
An increase in the total pressure of the system at constant temperature increases the equilibrium yield of CH3OH(g)\text{CH}_3\text{OH}(\text{g})CH3OH(g) and increases the value of KpK_pKp.
At constant pressure, decreasing the temperature of the reaction mixture decreases the value of KpK_pKp.
The equilibrium constant KpK_pKp has the unit kPa−2\text{kPa}^{-2}kPa−2 when the partial pressures of the gases are measured in kPa\text{kPa}kPa.
The addition of a copper-based catalyst increases the rate of the forward reaction to a greater extent than the reverse reaction, increasing the equilibrium yield.
31 exam-style questions on AQA A Level Chemistry Equilibrium constant $K_p$ for homogeneous systems (A-level only), covering Equilibrium constant $K_p$ for homogeneous systems (A-level only). Each one has a worked solution and a mark scheme showing where the marks go.