Testing for Gases

• What gases should you be able to test for by the end of the video?

  Hydrogen, oxygen, carbon dioxide, chlorine
• Why is it important to learn the tests for gases?

  They could appear in an exam and are easy to confuse
• What is the first step to test for hydrogen gas?

  Remove the bung and insert a burning splint
• What sound indicates the presence of hydrogen gas?

  A pop sound when it burns rapidly
• How do you test for oxygen gas?

  Use a glowing splint that bursts into flames
• What happens to a glowing splint in the presence of oxygen?

  It bursts into flames
• What is lime water used for in gas testing?

  To test for carbon dioxide gas
• What is lime water made of?

  Aqueous solution of calcium hydroxide
• What is the procedure to test for carbon dioxide using lime water?

  Bubble the gas through lime water
• What indicates that carbon dioxide is present when using lime water?

  The lime water turns cloudy
• How do you test for chlorine gas?

  Insert damp litmus paper into the test tube
• What happens to litmus paper when exposed to chlorine gas?

  It bleaches and turns white
• Where can you find more questions on testing for gases?

  In the vision workbook
• What are the tests for the four gases: hydrogen, oxygen, carbon dioxide, and chlorine?

  • Hydrogen: Burning splint produces a pop sound
  • Oxygen: Glowing splint bursts into flames
  • Carbon dioxide: Lime water turns cloudy
  • Chlorine: Damp litmus paper turns white