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Methanol is manufactured industrially by reacting carbon monoxide, CO\text{CO}CO, with hydrogen, H2\text{H}_2H2​.

The reaction is reversible, exothermic, and occurs in a closed system: CO(g)+2H2(g)⇌CH3OH(g)ΔH=−91 kJ mol−1\text{CO(g)} + 2\text{H}_2\text{(g)} \rightleftharpoons \text{CH}_3\text{OH(g)} \quad \Delta H = -91\text{ kJ mol}^{-1}CO(g)+2H2​(g)⇌CH3​OH(g)ΔH=−91 kJ mol−1

Only 10%10\%10% of the reactants are converted into methanol at each pass through the reactor. By cooling the mixture to condense and remove the methanol as a liquid, and then recycling the unreacted gases back into the reactor, it is possible to achieve an overall 95%95\%95% conversion.

The reaction is carried out under the following conditions:

  • Temperature: 250∘C250^\circ\text{C}250∘C
  • Pressure: 50−100 atm50-100\text{ atm}50−100 atm
  • Catalyst: Copper-based catalyst (Cu/ZnO/Al2O3\text{Cu}/\text{ZnO}/\text{Al}_2\text{O}_3Cu/ZnO/Al2​O3​)

Explain why these conditions and the recycling process are chosen for methanol production, referring to reaction rates, position of equilibrium, and economic factors.

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Equilibria Questions

Practise OCR GCSE Chemistry Equilibria with exam-style questions for Foundation and Higher tier. 35 questions, matched to the OCR GCSE Chemistry (J248) specification and written in Paper 1 and Paper 2 (Foundation Tier) or Paper 3 and Paper 4 (Higher Tier) style. Every question includes a full worked solution and mark scheme, so you can see where marks are awarded rather than just whether you got the answer right.

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