A technician takes gas samples from two process chambers, P and Q. Each chamber contains hydrogen, oxygen, carbon dioxide or chlorine. There is enough gas from each chamber to carry out separate tests.
| Process chamber | Observation with damp blue litmus paper | Observation with limewater |
|---|---|---|
| P | Turns red, then white | Stays clear |
| Q | No change | Stays clear |
Name the gas in chamber P. Explain how the results support your answer.
The technician concludes that chamber Q contains oxygen.
Explain why this conclusion is not justified. Give one further test and the result that would confirm that the gas is oxygen.
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.