Organic Chemistry

• Organic Compounds: Carbon-based molecules that contain carbon-hydrogen bonds.

  They are produced by or derived from living organisms

  Examples: Enzymes, Carbohydrates, proteins, fats
• An organic compound comprising only of carbon and hydrogen is called a hydrocarbon
• Petroleum is found in the remains of dead animals.
• Biofuels: Renewable energy sources to crude oil and natural gas.

  They come from plants or animals and can be replaced quick.

  For example, ethanol can be obtained from the fermentation of sugar in sugarcane. Sugarcane can be regrown fast, therefore ethanol from sugarcane is renewable.
• Homologous series: Same chemical properties, but different physical properties.

  Alkane:

  1. Methane CH4
  2. Ethane C2H5
  3. Propane C3H8
  4. Butane C4H10
• Alkene:

  1. Ethene C2H4
  2. Propene C3H6
  3. Butene C4H8
• Alkenes have double bonds. ( C=C double bond)
• Methane: Butane:

  H H H H

  H H- C - C - C - C -H

  H- C -H H H H H

  H

  Ethane:

  H H

  H - C - C - H

  H H
• Ethene:

  H H

  C=C

  H H
• Alkanes general formula: CnH2n+2
• Combustion: Alkane + Oxygen---> Carbon dioxide + Water
• Alkane---> Unreactive and saturated hydrocarbons
• Alkene ---> Reactive and unsaturated hydrocarbons
• Alkenes general formula: CnH2n
• Compounds that contain more than one pair of C=C are known as being polyunsaturated
• Alkenes are obtained from the cracking of large alkane molecules.

  Cracking---> to produce smaller and more useful alkene by using a catalyst--> speeds up the reaction
• Test for unsaturation using Aqueous bromine:

  Results:

  Alkane: Reddish brown aqueous turns colourless

  Alkene: No visible change