A water-treatment reaction changes a coloured pollutant into a colourless product. A technician carries out three runs using identical amounts of reactants at the same temperature. Each reaction is allowed to finish.
In run 3, all the substance Y recovered from run 2 is dried and reused.
| Run | Substance Y at the start in g | Time for the mixture to become colourless in s | Mass of product formed in g | Substance Y recovered at the end in g |
|---|---|---|---|---|
| 1 | 0 | 240 | 3.60 | not applicable |
| 2 | 1.50 | 54 | 3.60 | 1.48 |
| 3 | 1.48 | 56 | 3.60 | 1.46 |
Evaluate the evidence that substance Y acts as a reusable catalyst.
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.