4 test tubes are filled with oxygen, hydrogen, carbon dioxide and air. How to find out what gas is in each tidy.

To find out what gas is in each of the test tubes, it is enough to place a burning chip or match in each of them. In a test tube with carbon dioxide, the match will immediately go out. With oxygen, on the contrary, it will flare up with a bright strong flame. In a test tube with hydrogen, we will hear a pop, as if pulling a cork from a bottle (hydrogen burning with an explosion). A test tube with air remains. In it, a burning match will gradually go out as the oxygen burns out.