Chemistry Ozone

• How do you get from % to ppm

  X10,000
• Photon equation 


  Energy of photon = Planck constant x frequency
• Wave equation 


  Speed = frequency x wavelength
• Radiation’s of the suns in terms of the electromagnetic spectrum

  Visible light temporary reddening

  low ultraviolet quick tanning

  high energy uv tanning and sunburn
• Formation of ozone 


  O2 + O —> O3
• Destruction of ozone 


  Chlorine radicals are the catalyst for the breakdown of ozone
• Effects of ozone in the atmosphere 


  Absorbs high energy UV in the stratosphere
• Effects of ozone in the the troposhpere

  Harmful pollutant produces photochemical smog causing res issues
• Effects of high energy UV on human skin

  causes sunburn and an increased risk of skin cancer
• Effects of UV on promoting Electrons to higher energy levels 4 types

  Translation

  rotation

  vibration of bonds

  electron energy
• Photon to mole 


  X by avogadros constant
• Photon is equal to

  Bond energy
• 3 things can happen when a molecule absorbs UV radiation

  Ionisation electron is able to leave lots of radiation

  photodissociation radicals are formed

  electrons move between energy levels
• What is homolytic bond fission

  One of the 2 shared electrons goes to each atom
• what is heterolytic bond fission

  Common when a bond is polar both electrons go to one atom so one becomes positive one negative
• Define initiation, propagation, termination

  Initiation radicals are produced no radicals in reactant

  propagation radicals in both reactant and products

  termination radicals in reactants none in products
• imitation reaction named on spec

  Cfcl2 —> cf2cl + cl.
• Propagation reaction on spec

  Cl. + O3 —> clo. + O2
• Second propgation reaction on spec

  Clo. + O —> cl. + O2
• Effect of concentration and pressure on rate of reaction in terms of collision theory

  More pressurised increases rate of reaction as more collisions and if concentration increases so does the rate of reaction
• Activation enthalpy define 


  The nervy needed for a reaction to begin
• The hotter the temp the lower the peak and the further right it is
• Hotter the temp the speed of the molecules is faster so nearer the right also the higher the temp the higher the area beloe EA. meaning more successful collisions
• Role of catalysts 


  Providing alternative reaction pathways usually at a lower activation energy
• Homogeneous catalysts 


  In the same state as reactants
• Formation of intermediates 


  Catalysts forms an unstable product in the middle of the reaction
• Breakdown of ozone by haloalakanes

  Haloalkajes get into the stratosphere via natural processes molecules plot up by solar radiation which form halogen radicals that catalyse the breakdown of ozone
• Other ways ozone is removed

  Hydroxyl radical