In the Haber process, gaseous reactants form ammonia as they pass over an iron catalyst.
An engineer tests two operating pressures. The same quantities of the gaseous reactants and the same iron catalyst are used, and the temperature is kept constant.
The table shows the time taken to form 5.0 kg of ammonia.
| Test | Pressure in kPa | Time in s |
|---|---|---|
| R | 15 000 | 100 |
| S | 25 000 | 60 |
The engineer states, ‘The ammonia forms faster in test S because the higher pressure lowers the activation energy, in the same way as the iron catalyst.’
Evaluate the engineer’s statement using the data and collision theory.
122 exam-style questions on Edexcel GCSE Chemistry 8.1 Rates of reaction, covering 8.1.1 Measuring and interpreting rates of reaction, 8.1.2 Collision theory and the factors affecting rate, and 8.1.3 Catalysts and enzymes. Each one has a worked solution and a mark scheme showing where the marks go.