An industrial chemist tests four substances in a pilot reactor. Without any of these substances, the product forms at a rate of 0.40 mol/s.
The chemist tests 2.0 kg of each substance separately under the same conditions.
| Substance | Rate of product formation in mol/s\mathrm{mol/s}mol/s | Mass recovered after the reaction in kg\mathrm{kg}kg |
|---|---|---|
| P | 0.40 | 2.0 |
| Q | 0.95 | 1.3 |
| R | 1.05 | 2.0 |
| S | 0.25 | 2.0 |
Which substance acts as a catalyst?
Substance P
Substance S
Substance R
Substance Q
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.