Question 7
HAmmonia is made in the Haber process.
N2(g)+3H2(g)⇌2NH3(g) \mathrm{N_{2}(g) + 3H_{2}(g) \rightleftharpoons 2NH_{3}(g)} N2(g)+3H2(g)⇌2NH3(g)The forward reaction is exothermic.
The graph shows the percentage of ammonia in the equilibrium mixture under different conditions.
The table shows the relative rate of reaction at different temperatures, at 200 atm with an iron catalyst.
| Temperature (°C) | Relative rate of reaction |
|---|---|
| 300 | 1 |
| 400 | 7 |
| 500 | 35 |
| 600 | 140 |
a.[2]
Explain why the Haber process is so important in agricultural production.
b.[6]
A company is designing a new ammonia plant. It chooses a temperature of about 450 °C, a pressure of about 200 atm and an iron catalyst.
Explain why the company chooses these conditions.
Use the data in the graph and the table. Include ideas about rate, the position of equilibrium and cost.
c.[2]
The gas mixture leaving the reactor contains only about 15% ammonia.
Explain how the process still makes efficient use of the nitrogen and hydrogen.
6.1 Improving processes and products Questions
61 exam-style questions on OCR GCSE Chemistry 6.1 Improving processes and products, covering 6.1.1 Extracting metals industrially and by electrolysis, 6.1.2 Life cycle assessment and recycling, 6.1.3 Biological methods of metal extraction, 6.1.4 The Haber process and the production of fertilisers, 6.1.5 Alloys and their uses, 6.1.6 Corrosion and its prevention, 6.1.7 Comparing and selecting materials, and 6.1.8 Industrial conditions, rate and position of equilibrium. Each one has a worked solution and a mark scheme showing where the marks go.