8.23 - Chemical test for oxygen

Using a glowing splint

Oxygen is colourless, so appearance alone cannot identify it. Oxygen supports combustion: it enables fuel, such as wood, to burn more readily. Oxygen itself is not the fuel.

To test a small collected gas sample in a test tube or gas jar:

1. Light a wooden splint, then blow out its flame so that the tip still glows.
2. Put the glowing tip into the gas, keeping it out of any liquid reaction mixture.
3. Look for the splint to relight: a flame reappears.

Wear eye protection and handle the hot splint carefully during supervised practical work.

[DIAGRAM: asset_name: oxygen_glowing_splint_test: Oxygen glowing-splint gas test - diagram 1; asset_slug: 201_8_23_chemical_test_for_oxygen_diagram1; file: 201_8_23_oxygen_test_corrected_v2.png; recommended_method: deterministic_drawn; description: Two panels show the lower glowing tip inserted inside a gas sample and then relighting inside the tube. Oxygen supports combustion.]

The initial splint must be glowing without a flame. If it is already burning, saying “it burns” does not demonstrate relighting.