This topic summary covers Topic Summary: Gas Tests within Gas Tests for GCSE Chemistry. Revise Gas Tests in Chemical Analysis for GCSE Chemistry with 20 exam-style questions and 15 flashcards. This is a high-frequency topic, so it is worth revising until the explanation feels precise and repeatable. It is section 13 of 13 in this topic. Use this topic summary to connect the idea to the wider topic before moving on to questions and flashcards.
Topic position
Section 13 of 13
Practice
20 questions
Recall
15 flashcards
Topic Summary: Gas Tests
Hydrogen
- Test: lit/burning splint
- Result: squeaky pop
- Equation: 2H₂ + O₂ → 2H₂O
- Hazard: highly flammable
Oxygen
- Test: glowing splint
- Result: splint relights
- Explanation: supports combustion
- Note: GLOWING not burning
Carbon Dioxide
- Test: bubble through limewater
- Result: turns milky/cloudy
- Product: CaCO₃ (white precipitate)
- Excess CO₂ clears the solution
Chlorine and Ammonia
- Cl₂: damp BLUE litmus → bleaches white
- NH₃: damp RED litmus → turns blue
- NH₃ also: white fumes with HCl rod
- Both need DAMP litmus