Nickel catalyses the addition of hydrogen to an unsaturated oil. A student follows the reaction by measuring the volume of hydrogen remaining. The gas is kept at the same temperature and pressure throughout.
| Time in s | 0 | 30 | 60 | 90 |
|---|---|---|---|---|
| Volume of hydrogen remaining in cm3\mathrm{cm^{3}}cm3 | 80 | 62 | 50 | 44 |
Calculate the percentage decrease in the mean rate at which hydrogen is used up, from the first 30 s shown to the final 30 s shown.
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.