In a food factory, vegetable oil is hardened by reacting it with hydrogen gas in a reactor that contains a nickel catalyst. Engineers test the reactor at three pressures of hydrogen. The temperature, the mass of oil and the mass of nickel are the same in each test.
The table shows the time taken for all of the oil to react at each pressure.
| Pressure of hydrogen (kPa) | Time (min) |
|---|---|
| 200 | 50 |
| 300 | 35 |
| 400 | 26 |
Describe and explain the pattern in the results. Use ideas about particles.
Each batch of oil must react completely in 40 minutes or less, and the pressure in the reactor must not exceed 350 kPa.
Which of the tested pressures should be used? Give reasons for your answer.
122 exam-style questions on OCR GCSE Chemistry 5.2 Controlling reactions, covering 5.2.1 Measuring and interpreting rate of reaction, 5.2.2 Factors affecting rate and collision theory, and 5.2.3 Catalysts, activation energy and enzymes. Each one has a worked solution and a mark scheme showing where the marks go.