The table shows how temperature affects the rate of the Haber process reaction and the percentage of ammonia in the mixture at equilibrium. The pressure is 200 atmospheres.
| Temperature (∘C^\circ\mathrm{C}∘C) | Relative rate | Percentage of ammonia at equilibrium (%) |
|---|---|---|
| 350 | 1 | 45 |
| 400 | 3 | 36 |
| 450 | 8 | 28 |
| 500 | 20 | 20 |
Which statement is supported by the data?
From 400 ∘C400\,^\circ\mathrm{C}400∘C to 500 ∘C500\,^\circ\mathrm{C}500∘C, the rate doubles and the percentage of ammonia halves.
From 350 ∘C350\,^\circ\mathrm{C}350∘C to 450 ∘C450\,^\circ\mathrm{C}450∘C, the rate is 8 times greater and the percentage of ammonia falls by 17 percentage points.
For every 50 ∘C50\,^\circ\mathrm{C}50∘C rise, the percentage of ammonia at equilibrium falls by the same amount.
At 500 ∘C500\,^\circ\mathrm{C}500∘C, equilibrium is reached 20 times more slowly than at 350 ∘C350\,^\circ\mathrm{C}350∘C.
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.