Identical surfaces coated with amylase are placed in starch solutions. Amylase catalyses the breakdown of starch into sugars.
Both experiments are carried out at the same temperature.
| Experiment | Volume of starch solution in cm3\mathrm{cm^3}cm3 | Relative concentration of starch | Mass of sugars formed in the first 2.0 minutes in g\mathrm{g}g | Final mass of sugars formed in g\mathrm{g}g |
|---|---|---|---|---|
| P | 20 | 3.0 | 0.32 | 1.30 |
| Q | 30 | 2.0 | 0.22 | 1.30 |
Calculate the mean rate of formation of sugars during the first 2.0 minutes in each experiment.
Explain why the mean rates are different but the final masses of sugars are the same.
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.