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Contents contributed and discussions participated by Shirley Lu

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The Haber Process for the manufacture of ammonia - 0 views

www.chemguide.co.uk/...haber.html
shared by Shirley Lu on 14 Feb 13 - Cached
    • Shirley Lu
      Shirley Lu on 14 Feb 13
       
      moderate temperature is used -- seemingly contradicts Le Chatelier's Principle but decreasing temperature will cause the reaction to happen uneconomically slow
  • Recycling
    • Shirley Lu
      Shirley Lu on 14 Feb 13
       
      economic reasons
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Case Study: The Haber Process - ChemWiki - 3 views

chemwiki.ucdavis.edu/...Haber_Process
shared by Amy Chern on 14 Feb 13 - No Cached
  • commercial synthesis of ammonia
    • Shirley Lu
      Shirley Lu on 14 Feb 13
       
      production of ammonia with maximum efficiency
  • conditions for the formation of ammonia
    • Shirley Lu
      Shirley Lu on 14 Feb 13
       
      conditions for highest yield
  • work of high-pressure on chemical reactions (developed into industrial process)
    • Shirley Lu
      Shirley Lu on 14 Feb 13
       
      effects of pressure -- increased pressure --> increased yield
  • ...8 more annotations...
  • During the 1920’s, there was a shortage of the world's supply for fixed nitrogen.
    • Shirley Lu
      Shirley Lu on 14 Feb 13
       
      historical background -- was in high demand
  • mainly used for fertilizer
    • Shirley Lu
      Shirley Lu on 14 Feb 13
       
      fertilizer --> agricultural importance -- crucial to maintain food supply (especially during wartime)
  • N2(g) + 3H2(g) → 2NH3(g)     ΔH=-92.4 kJ
    • Shirley Lu
      Shirley Lu on 14 Feb 13
       
      forward, exothermic reaction; all reactants and products are in gas state
  • 2NH3(g) → N2(g) + 3H2(g)     ΔH=+ 92.4 kJ mol-1
    • Shirley Lu
      Shirley Lu on 14 Feb 13
       
      reverse, endothermic reaction
  • takes place under high pressure and temperature and with an iron catalyst***
    • Shirley Lu
      Shirley Lu on 14 Feb 13
       
      shifts equilibrium to right, pushing forward reaction to maximize yield of ammonia
    • Shirley Lu
      Shirley Lu on 14 Feb 13
       
      enthalpy diagram -- catalysed has lower activation energy
    • Shirley Lu
      Shirley Lu on 14 Feb 13
       
      applications of Le Chatelier's Principle
  • When you increase the pressure so that the least amount of molecules will be formed, there won't be an increase in collisions. However, if more gas molecules are formed, there will be an increase in collisions, thus moving the way that will produce the least amount of molecules.
    • Shirley Lu
      Shirley Lu on 14 Feb 13
       
      explanation using collision theory
  • Shirley Lu on 14 Feb 13
     
    Shirley Lu
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Gale Science In Context - Document - 2 views

ic.galegroup.com/...DocumentToolsPortletWindow
shared by Shirley Lu on 14 Feb 13 - No Cached
  • boiling point -28.03°F [-33.35°C]
    • Shirley Lu
      Shirley Lu on 14 Feb 13
       
      gas at room temperature
  • 200,000 tons of ammonia were released into the environment
    • Shirley Lu
      Shirley Lu on 14 Feb 13
       
      negative environmental impact
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