An analytical chemist is investigating an unknown mineral sample extracted from a geothermal vent. They perform two qualitative tests to identify its constituent ions:
| Test | Observation | |
|---|---|---|
| Test 1 | A sample is moistened with concentrated hydrochloric acid and heated on a clean nichrome wire in a roaring Bunsen flame | A brick-red flame is produced |
| Test 2 | Dilute hydrochloric acid is added to the solid mineral sample | Rapid effervescence is observed, and the evolved gas turns limewater cloudy |
State the name of the gas given off in Test 2.
Practise Edexcel GCSE Chemistry Qualitative analysis: tests for ions with exam-style questions for Foundation and Higher tier. 127 questions, matched to the Edexcel GCSE Chemistry (1CH0) specification and written in Paper 1 and Paper 2 style. Every question includes a full worked solution and mark scheme, so you can see where marks are awarded rather than just whether you got the answer right.
