Organic Chemistry

• Alkane


  General formula : CₙH₂ₙ₊₂
• Alkene


  General formula: CₙH₂ₙ
• Alkene


  Functional group: -C=C-
• Alcohol


  General formula: CₙH₂ₙ₊₁OH
• Alcohol


  Functional group: -OH
• Carboxylic Acid


  General formula: CₙH₂ₙ₊₁COOH
• Carboxylic Acid


  Functional group: -COOH
• Ester


  Functional group: -COO-
• Reactions - Compete combustion


  hydrocarbon + oxygen -> carbon dioxide + water vapour
• Reactions - Incomplete combustion


  alkene + oxygen -> carbon + carbon monoxide + carbon dioxide + water
• Reactions - Cracking


  long chain alkanes -> short chain alkanes + alkenes
• Reactions - Hydrogenation


  alkene + hydrogen -> alkane
• Reactions - Alcohol Production


  alkene + water -> alcohol
• Reactions - Adding a halogen


  alkene + halogen -> haloalkane

  eg.

  methene + chlorine -> chloromethane
• Reactions - Polymerisation

  alkene + pressure + catalyst -> poly(alkene)
• Reactions - Fermentation

  Sugar -> Carbon dioxide + alcohol

  Yeast is required as a catalyst
• Reactions - Oxidation


  alcohol + oxygen -> carboxylic acid
• Reactions - Esterification

  alcohol + carboxylic acid -> ester + water

  Acid is required as a catalyst
• Reactions - Condensation polymerisation - polyester


  dicarboxylic acid + diol -> polyester

  Ester link is created
• Shorter chain alkanes are less viscous, more flammable and have lower condensing and vapourising points
• Cracking

  Catalytic Cracking

  • lower temperature
  • high pressure
  • (eg) aluminium oxide catalyst

  Steam Cracking

  • this is thermal decomposition
  • Very high temperature
  • high pressure
  • steam
• Alkane vs Alkene test

  • Alkene causes a colour change of bromine water from orange to colourless
  • This is because alkenes are unsaturated
  • The C=C bond breaks becoming C-C leaving a bond for bromine
• First 4 alcohol's properties

  • flammable
  • dissolve completely in water forming pH 7
  • react with sodium producing hydrogen
  • oxidised to make carboxylic acid
• Fermentation

  reaction is quickest at:

  • 37°C
  • slightly acidic
  • anaerobic
• Properties of Carboxylic acids:

  • React like normal acids
  • partially ionise in water creating a weak acid
• Naming hydrocarbons

  NUMBER OF CARBONS : PREFIX

  1 : meth

  2: eth

  3: prop

  4: but

  5: pent

  6: hex