A technician is developing a warning label for chlorine gas. Each prototype contains red litmus paper and is exposed to chlorine for the same length of time.
| Prototype | Preparation before exposure | Observation in chlorine |
|---|---|---|
| A | Paper kept dry | Remained red |
| B | Paper dampened immediately before exposure | Turned white |
| C | Paper dampened when made, then stored until dry | Remained red |
A company proposes to make the labels by dampening the paper and then storing them until they are needed.
Use the results in the table to evaluate the company's proposal. Suggest one change that would make the label give a positive result when chlorine is present.
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.