Two clear, colourless solutions, reactant X and reactant Y, react together in a conical flask to produce a cloudy white precipitate.
To investigate how different factors affect the rate of this reaction, a student placed the conical flask on top of a sheet of paper marked with a black circle. They measured the time taken for the precipitate to completely obscure the circle when viewed from above.
Their results are shown in the table below:
| Experiment | Concentration of reactant X in mol/dm3\text{mol/dm}^3mol/dm3 | Temperature in ∘C^{\circ}\text{C}∘C | Time taken for circle to disappear in s\text{s}s |
|---|---|---|---|
| 1 | 0.1 | 25 | 240 |
| 2 | 0.1 | 45 | 60 |
| 3 | 0.4 | 45 | 15 |
Use the results in the table to explain, in terms of collision theory, the effect of changing the temperature and the effect of changing the concentration of reactant X on the rate of this reaction.
87 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.