Methanol is made industrially by reacting carbon monoxide with hydrogen in a reversible reaction.
CO(g)+2H2(g)⇌CH3OH(g)\mathrm{CO(g)} + 2\mathrm{H_{2}(g)} \rightleftharpoons \mathrm{CH_{3}OH(g)}CO(g)+2H2(g)⇌CH3OH(g)
The table shows the percentage of methanol in the equilibrium mixture under different conditions.
| Temperature / °C | Percentage of methanol at 50 atm / % | Percentage of methanol at 100 atm / % |
|---|---|---|
| 200 | 60 | 75 |
| 250 | 40 | 58 |
| 300 | 20 | 35 |
Deduce whether the forward reaction is exothermic or endothermic. Justify your answer using the data.
Explain why the percentage of methanol is higher at 100 atm than at 50 atm.
Calculate the maximum mass, in kg, of methanol that can be made from 7.0 kg of carbon monoxide. Relative formula masses: CO=28,CH3OH=32\mathrm{CO} = 28, \mathrm{CH_{3}OH} = 32CO=28,CH3OH=32
The company uses a temperature of 250 °C, a pressure of 100 atm and a copper-based catalyst. Explain why these conditions are chosen. Use the data and your knowledge of rate, yield and cost in your answer.
43 exam-style questions on Edexcel GCSE Chemistry 6.3 Dynamic equilibria, covering 6.3.1 The Haber process as a reversible reaction, 6.3.2 Conditions and rate in industrial equilibria, and 6.3.3 Fertilisers and the preparation of ammonium sulfate. Each one has a worked solution and a mark scheme showing where the marks go.