Identification of Common Gases

Hydrogen
The test for hydrogen uses a burning splint held at the open end of a test tube of the gas. Hydrogen burns rapidly with a pop sound.

Oxygen
The test for oxygen uses a glowing splint inserted into a test tube of the gas. The splint relights in oxygen.

Carbon dioxide
The test for carbon dioxide uses an aqueous solution of calcium hydroxide (lime water). When carbon dioxide is shaken with or bubbled through limewater the limewater turns milky (cloudy).

Chlorine
The test for chlorine uses litmus paper. When damp litmus paper is put into chlorine gas the litmus paper is bleached and turns white.