A reaction between two solutions causes a colour change. A student records the mean time for the colour change to reach the same stage at three temperatures. All other conditions are kept the same.
| Temperature in ∘C^\circ\mathrm{C}∘C | Mean time in s\mathrm{s}s |
|---|---|
| 15 | 158 |
| 25 | 81 |
| 35 | 40 |
Explain the pattern in the results. In your answer, include a prediction for the mean time at 45 ∘C45\,^\circ\mathrm{C}45∘C.
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.