A compound decomposes to form a gaseous product.
A technician carries out the reaction twice using the same mass of the compound, the same apparatus and the same temperature. A catalyst is added only in reaction 2. Both reactions are allowed to go to completion.
| Time in s | Volume of gas in reaction 1 in cm3\text{cm}^3cm3 | Volume of gas in reaction 2 in cm3\text{cm}^3cm3 |
|---|---|---|
| 0 | 0 | 0 |
| 40 | 19 | 31 |
| 80 | 33 | 40 |
| 120 | 40 | 40 |
| 160 | 40 | 40 |
Use the results to compare the rate and the final volume of gas for the two reactions.
Explain why reaction 2 has a different rate from reaction 1.
127 exam-style questions on AQA GCSE Chemistry 6.1 Rate of reaction, covering 6.1.1a Calculating rates of reactions, 6.1.1b Gradient of a tangent as rate, 6.1.2 Factors which affect the rates of chemical reactions, 6.1.3 Collision theory and activation energy, and 6.1.4 Catalysts. Each one has a worked solution and a mark scheme showing where the marks go.