Gases in the atmosphere

• Gases in the atmosphere

  • Oxygen
  • Nitrogen
  • Carbon Dioxide
  • Water Vapour
  • Methane
  • Argon
• Today's atmosphere differs from the atmosphere 4.5 billion years ago


  • Carbon Dioxide
  • Water Vapour
  • Methane
  • Nitrogen
  • Argon
  • Oxygen
• Demo: How can we know there is approx. 21% Oxygen in Air?

  1. Start with 100 cm3 of air in the syringe

  2. Burn Cu in this air

  3. Air passes backward/forward across Cu

  4. When the volume of air stops moving / getting smaller the remaining volume is recorded when cooled to room temperature
• Demo: How can we know there is approx. 21% Oxygen in Air?

  1. Draw the experiment

  2. Describe how to carry out the experiment

  3. Make a prediction

  4. Write what you observe during the demo

  5. Explain the chemistry behind why you have observed this

  6. Write the chemical word and balance symbol equation showing the reaction that is occurring

  7. Why must we measure the final volume at room temperature
• Percentage of nitrogen in the air


  78%
• Percentage of oxygen in the air 


  21%
• Percentage of carbon dioxide in the air

  0.04%
• Percentage of other gasses in the air

  0.96%