chemistry of the atmosphere

• The early atmosphere (4.6 billion years ago) consisted of

  • H2O - water
  • CH4 - Methane
  • NH3 - Ammonia
  • N2 - Nitrogen
• Volcanoes erupted releasing an enormous amount of Carbon Dioxide, water vapour and some Nitrogen, methane and ammonia

  • the planet was very hot, and there was no plant or animal life
• after the earth cooled, the water vapour condensed and formed oceans
• where did all the CO2 go?

  dissolved in oceans, photosynthesis, trapped in rocks
• where has all the O2 come from?

  released from photosynthesis
• where has all the Nitrogen come from?

  Ammonia reacted with Oxygen, forming Nitrogen and water
• Ammonia + Oxygen → Nitrogen + Water


  4NH3(g) + 3O2(g) → 2N2(g) + 6H2O(l)
• why did Nitrogen continue to rise in the atmosphere?

  Nitrogen is a triple bond so the electrons are held together with strong intermolecular forces
• the greenhouse effect is the retention of heat in the atmosphere due to greenhouse gases
• common greenhouse gases are:

  • Carbon Dioxide
  • Methane
  • water
• The greenhouse effect:

  • short wave radiation emitted by the sun
  • short wave radiation can pass through the atmosphere
  • long wave Infared radiation is trapped by greenhouse gases
  • the atmosphere is heated up
• a Carbon footprint is a measure of the amount of Carbon and other greenhouse gases that are released over the full life cycle of something
• ways to reduce Carbon footprint

  • use renewable energy sources or nuclear energy
  • encourage people to use less emissions
  • governments could tax companies based off amount of emissions released
  • Carbon storage
• problems with reducing Carbon footprints

  • most countries don't want to sacrifice their economic development if others won't do the same
  • inconvenience
• percent of Oxygen in todays atmosphere

  21%
• percent of Nitrogen in todays atmosphere

  78%
• primary pollutants are produced at the source of burning fossil fuels
• secondary pollutants are produced by primary pollutants reacting further in the atmosphere
• Carbon Dioxide


  formed by complete combustion, is a greenhouse gas and contributes to global warming
• Carbon Monoxide (and particulates)


  formed by incomplete combustion, causes respiratory problems and global dimming
• Nitrogen Oxide


  formed inside hot engines during combustion, causes acid rain and respiratory issues
• Sulfur Dioxide


  formed by impurities in fuel, causes acid rain
• a catalytic converter is fitted into a vehicle to change Carbon Monoxide, particulates and Nitrous Oxide into less harmful substances such as Carbon Dioxide and water