What is the test for oxygen gas?

The test for oxygen gas involves inserting a glowing splint into the gas. When oxygen is present, the glowing splint will reignite, indicating that oxygen supports combustion. This characteristic reaction is due to oxygen's role as a key oxidizing agent; it readily reacts with many substances, particularly those that are combustible. The glowing splint provides just the right conditions for this to happen, as the splint contains enough heat to start a reaction when combined with the oxygen in the air.

Other methods, such as using a matchstick to create a small flame or observing changes in litmus paper, do not specifically indicate the presence of oxygen. Bubbling gas through water may not effectively show the gas's properties or confirm its identity. Thus, the glowing splint test is a direct and reliable method for identifying the presence of oxygen in a sample.