A chemist tests a small sample of gas from a chemical process.
The chemist puts the same volume of the gas and the same volume of fresh limewater into each of three sealed sample bottles. Each bottle is turned upside down and back a different number of times. The appearance of the limewater is recorded after 30 seconds.
| Bottle | Number of times turned upside down and back | Appearance of limewater after 30 seconds |
|---|---|---|
| P | 0 | clear |
| Q | 5 | slightly cloudy |
| R | 20 | cloudy white |
Use the results to explain why bottle R gives the strongest evidence that the gas is carbon dioxide.
89 exam-style questions on AQA GCSE Chemistry 8.2 Identification of common gases, covering 8.2.1 Test for hydrogen, 8.2.2 Test for oxygen, 8.2.3 Test for carbon dioxide, and 8.2.4 Test for chlorine. Each one has a worked solution and a mark scheme showing where the marks go.