Chemistry

• Fractionating column


  1. At different temperatures

  2. Each fraction contains hydrocarbon molecules with a similar number of carbon atoms
• Cracking


  Breaking down of larger hydrocarbon molecules into smaller, more useful ones
• Methane


  • Chemical formula: CH4
• Ethane


  • Chemical formula: C2H6
• Propane


  • Chemical formula: C3H8
• Butane


  • Chemical formula: C4H10
• Pentane


  • Chemical formula: C5H12
• Longer hydrocarbon molecule


  Contains more carbon atoms and higher boiling point.
• Higher boiling point


  Less volatile and boiling point
• Higher boiling point


  More viscous
• Large hydrocarbon molecules are useful as fuels
• Fractional distillation


  1. Crude oil is heated to 350°C

  2. Vapours allowed to condense at different temperatures in the fractionating column

  3. Each fraction contains hydrocarbon molecules with a similar number of carbon atoms
• Homologous Series


  A series of molecules with the same general formula, each subsequent member differs by -CH2
• Alkanes


  • Saturated hydrocarbons
  • Only contain single covalent bonds
• Homologous


  A series of molecules with the same general formula, each subsequent member differing by -CH₂
• Element


  A substance made up of only one type of atom
• Main elements in living things

  • Carbon
  • Hydrogen
  • Nitrogen
• Elements in coins


  • Nickel
  • Zinc
• Diamonds and coal


  Both contain carbon
• Atom


  The smallest particle
• Element


  Made up of only 1 type of atom
• Compound


  Two or more different atoms that are chemically joined
• Mixture


  Two or more different atoms that aren't chemically joined
• Molecule


  Two or more atoms chemically joined
• Alkene normal formula - CnH2n+2