Chemistry, 14: Organic chemistry

• Name and draw CH4

  methane

  H

  H - C - H

  H
• Name and draw C2H6

  Ethane

  H H

  H-C - C - H

  H H
• Name and draw C2H4

  Ethene

  H H

  C = C

  H H
• Name and draw C2H5OH

  H H

  H - C - C - O - H

  H H
• A hydrocarbon is a compound that contains only hydrogen and carbon atoms
• The general formula states the ratio

  E.g., C3H8
• The structural formula shows the arrangement of atoms in a molecule

  E.g.

  H H H

  H - C - C - C - H

  H H H
• The displayed formula shows the symbol for each atom in the compound

  E.g., CH3CH2CH3
• Compounds ending in …ane are in the alkane family

  They have no functional group
• Compounds ending in …ene are in the alkene family

  They are part of the C=C functional group
• Compounds ending in …anol are part of the alcohol family

  They are part of the -OH functional group
• Name and draw C3H6

  Propene

  H. H

  C = C - C - H

  H H H
• Name and draw C4H8

  Butene

  H. H H

  C = C - C - C - H

  H H H H
• What produces carbon dioxide on combustion?

  Coal

  Natural gas

  Fossil fuel
• Methane is the main constituent of natural gas
• Petroleum (crude oil) is a mixture of hydrocarbons which can be separated into useful fractions via fractional distillation
• Smalller hydrocarbon chains have the lowest boiling point, and rises up the column and condenses at the top to be collected.
• Larger hydrocarbons have a higher boiling point and is collected at the bottom of the column
• Smaller hydrocarbons are light coloured runny liquids
• Longer hydrocarbons are dark, sticky, and viscous.
• The longer the molecule, the stronger the intermolecular force and therefore the lower down the fraction it is.
• Shorter hydrocarbons are more volatile and forms vapour easily
• Shorter hydrocarbons burn more easily, meanwhile longer hydrocarbons are harder to burn.
• Shorter hydrocarbons have a blue flame with almost no smoke, meanwhile longer hydrocarbons have a smoky yellow flame
• Refinery gas, a short chain hydrocarbon, can be used as bottled gas for heating and cooking
• Gasoline can be used as fuel in cars
• Naptha is used as a feedstock for making chemicals
• Diesel is used as fuel in diesel engines
• Bitumen is used for road surfaces
• Lubricating oil is used for lubricants, waxes, and polishes.
• Kerosene is used for jet fuel
• Name the fractions


  (Top to bottom)

  • Refinery gas
  • Gasoline
  • Naptha
  • Kerosene
  • Diesel
  • Fuel
  • Lubricant
  • Bitumen
• The homologous series is a group of compounds that have the same functional group and the same general formula along with similar chemical properties.
• What do all members of the homologous series have?

  Same general formula

  Same functional group

  Similar chemical properties
• What is the formula for alkanes?


  CnH2n + 2
• What is the formula for alkenes?

  CnH2n
• What is the formula for alcohols?


  CnH(2n+1)OH
• Alkanes are saturated, they only contain a single bond between the carbon atoms
• Alkanes are obtained from crude oil via fractional distillation
• Alkanes are mostly un-reactive, apart from burning