Substance Y is manufactured from gas X in a closed reactor. The forward reaction is exothermic.
2X(g)⇌Y(g)2\text{X}(\text{g}) \rightleftharpoons \text{Y}(\text{g})2X(g)⇌Y(g)
The table shows the results from three experiments.
| Experiment | Temperature in ∘C^\circ\text{C}∘C | Pressure in atmospheres | Equilibrium yield of Y in % | Time taken to reach equilibrium in min |
|---|---|---|---|---|
| 1 | 300 | 50 | 82 | 25 |
| 2 | 450 | 20 | 49 | 9 |
| 3 | 450 | 50 | 64 | 7 |
Explain the difference between the equilibrium yields of Y in experiments 2 and 3.
The equilibrium yield of Y must be at least 60% and the mixture must reach equilibrium in no more than 8 minutes.
Explain which experiment should be chosen. In your answer, explain why the equilibrium yield in experiment 1 is greater than in experiment 3.
109 exam-style questions on AQA GCSE Chemistry 6.2 Reversible reactions and dynamic equilibrium, covering 6.2.1 Reversible reactions, 6.2.2 Energy changes and reversible reactions, 6.2.3 Equilibrium, 6.2.4 The effect of changing conditions on equilibrium, 6.2.5 The effect of changing concentration, 6.2.6 The effect of temperature changes on equilibrium, and 6.2.7 The effect of pressure changes on equilibrium. Each one has a worked solution and a mark scheme showing where the marks go.