To test for the presence of oxygen in a gas sample, you will need a test tube that contains the gas. The following steps can be followed to perform the test:
1. Obtain a test tube and add the gas sample you wish to test.
2. Remove the bung or stopper from the test tube, then take a glowing splint and insert it into the test tube through the open end.
3. Observe the reaction of the splint. If the test tube contains oxygen, the splint will relight and produce a flame.
It is important to exercise caution when handling gases, as some may be flammable or toxic.