| Gas | Density vs Air | Solubility | Collection Method |
|---|---|---|---|
| H₂ | Less dense | Low | Downward delivery or over water |
| O₂ | Similar density | Low | Over water |
| CO₂ | Denser | Medium | Upward delivery |
| Cl₂ | Much denser | Medium | Upward delivery |
| NH₃ | Less dense | Very high | Downward delivery only |
This key facts covers Gas Collection Methods within Gas Tests for GCSE Chemistry. Revise Gas Tests in Chemical Analysis for GCSE Chemistry with 20 exam-style questions and 15 flashcards. This topic appears regularly enough that it should still be part of a steady revision cycle. It is section 10 of 13 in this topic. Use this key facts to connect the idea to the wider topic before moving on to questions and flashcards.
Practice questions for Gas Tests
Which observation confirms a gas is hydrogen when tested with a burning splint?
Explain why hydrogen gas produces a squeaky pop when tested with a burning splint.
Quick recall flashcards
Test for hydrogen gas (H₂)?
Use a burning splint. POSITIVE RESULT: 'Squeaky pop' sound (H₂ burns rapidly: 2H₂ + O₂ → 2H₂O)
Test for oxygen gas (O₂)?
Use a glowing splint (blow out flame first). POSITIVE RESULT: Glowing splint relights/bursts into flame (O₂ supports combustion)