A chemist investigates the effect of two solid transition-metal compounds, P and Q, on a reaction between two solutions. In each experiment, the time taken to collect 50 cm³ of gas is measured. Any solid remaining at the end is recovered, dried and weighed.
| Solid added | Initial mass of solid in g | Time taken to collect 50 cm³ of gas in s | Mass of solid remaining in g |
|---|---|---|---|
| None | 0.00 | 210 | 0.00 |
| P | 1.50 | 72 | 1.50 |
| Q | 1.50 | 48 | 0.65 |
Explain which solid, P or Q, is a catalyst for this reaction. Use data from the table in your answer.
91 exam-style questions on AQA GCSE Chemistry 1.3 Properties of transition metals, covering 1.3.1 Comparison with Group 1 elements and 1.3.2 Typical properties of transition metals. Each one has a worked solution and a mark scheme showing where the marks go.