A gas, R, is made in a closed reactor.
2P(g)+Q(g)⇌R(g) \mathrm{2P(g) + Q(g) \rightleftharpoons R(g)} 2P(g)+Q(g)⇌R(g)The forward reaction is exothermic.
The table shows the percentage yield of R at equilibrium under different conditions.
| Temperature (°C) | Pressure (kPa) | Percentage yield of R |
|---|---|---|
| 350 | 100 | 42 |
| 450 | 100 | 28 |
| 350 | 300 | 66 |
| 450 | 300 | 51 |
The reactor is initially at 350 °C and 100 kPa. The temperature and pressure are then increased at the same time to 450 °C and 300 kPa.
Explain whether the percentage yield of R increases or decreases. Use the equation and all the data in the table in your answer.
124 exam-style questions on OCR GCSE Chemistry 5.3 Equilibria, covering 5.3.1 Reversible reactions and dynamic equilibrium and 5.3.2 Changing the position of equilibrium. Each one has a worked solution and a mark scheme showing where the marks go.