Identification of common gases

• What is the test for hydrogen gas?

  Use a burning splint held at the open end of a test tube of the gas.
• What sound indicates the presence of hydrogen when tested?

  A 'squeaky pop' sound is produced.
• What is the test for oxygen gas?

  Use a glowing splint inserted into a test tube of the gas.
• What happens to a glowing splint when it is placed in oxygen?

  The splint relights in oxygen.
• What is the test for carbon dioxide gas?

  Bubble the gas through limewater (calcium hydroxide (aq)).
• What observation indicates the presence of carbon dioxide when tested with limewater?

  The limewater will turn milky (cloudy).
• What is the test for chlorine gas?

  Use damp litmus paper.
• What happens to damp litmus paper when exposed to chlorine gas?

  The litmus paper is bleached and turns white.
• What are the tests for the four gases: hydrogen, oxygen, carbon dioxide, and chlorine?

  • Hydrogen: Burning splint produces a 'squeaky pop'.
  • Oxygen: Glowing splint relights.
  • Carbon Dioxide: Bubbles through limewater turns milky.
  • Chlorine: Damp litmus paper bleaches and turns white.