A gas supplier checks three unlabelled samples, P, Q and R, before attaching labels. The samples are hydrogen, oxygen and chlorine, with each gas present in one sample only.
The supplier tests samples P and Q.
| Sample | Test carried out | Result |
|---|---|---|
| P | A lit splint was held at the open end of the test tube. | A squeaky pop was heard. |
| Q | Damp blue litmus paper was held in the gas. | The paper was bleached white. |
Explain how the results can be used to identify the gas in sample R.
Describe a test that could confirm the identity of sample R. Predict the result and explain why this result would occur.
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.