In the industrial synthesis of methanol, carbon monoxide and hydrogen gas are reacted reversibly in the presence of a solid copper-based catalyst:
CO(g)+2H2(g)⇌CH3OH(g)ΔHθ=−90 kJ mol−1 \text{CO}(\text{g}) + 2\text{H}_2(\text{g}) \rightleftharpoons \text{CH}_3\text{OH}(\text{g}) \quad \Delta H^{\theta} = -90 \text{ kJ mol}^{-1} CO(g)+2H2(g)⇌CH3OH(g)ΔHθ=−90 kJ mol−1Which of the following statements correctly describes the effect of introducing this catalyst to the system?
The rate of the forward reaction increases, whereas the rate of the reverse reaction decreases.
The activation energy for both the forward and reverse reactions is reduced by the same amount, decreasing the time required to reach equilibrium.
The equilibrium yield of methanol increases because the catalyst provides an alternative reaction pathway of lower energy.
The equilibrium constant KcK_cKc increases because the rate of the forward reaction is enhanced to a greater extent than the reverse reaction.
25 exam-style questions on OCR GCSE Chemistry Equilibria. Each one has a worked solution and a mark scheme showing where the marks go.