Give tests for oxygen gas.

Here are some common tests to detect the presence of oxygen gas:

Relighting a glowing splint: This is a classic test for oxygen. Take a wooden splint, ignite it until it's glowing, and then blow it out. Place the glowing end of the splint into a test tube or container suspected to contain oxygen gas. If the splint reignites, it indicates the presence of oxygen.

Combustion test: Oxygen is a supporter of combustion. You can test for its presence by bringing a glowing object or a flammable material, such as a piece of wood or a matchstick, close to the suspected source of oxygen gas. If the object catches fire more readily or burns more intensely, it suggests the presence of oxygen.

Effervescence with hydrogen peroxide: Oxygen gas can be detected by reacting hydrogen peroxide (H₂O₂) with a catalyst, such as manganese dioxide (MnO₂). Add a small amount of manganese dioxide to a container, then pour in hydrogen peroxide. If the reaction produces effervescence (bubbling), it indicates the release of oxygen gas.

Limewater test: This test is based on the reaction between oxygen gas and calcium hydroxide (Ca(OH)₂), forming calcium carbonate (CaCO₃). Pass the suspected oxygen gas through a glass tube into a container of limewater (a saturated solution of calcium hydroxide). If the limewater turns milky or cloudy due to the formation of calcium carbonate, it suggests the presence of oxygen.

Oxidation of a substance: Oxygen gas can often cause oxidation reactions. You can test for its presence by exposing a substance to the suspected oxygen gas and observing if any noticeable oxidation occurs. This could involve the tarnishing of metals or the browning of certain chemicals.

Remember to exercise caution and conduct these tests in a controlled environment with appropriate safety measures.