AQA GCSE Chemistry Trilogy: Hydrocarbons and Alkanes

Crude Oil:

  • Hydrocarbons are compounds that contain hydrogen and carbon atoms only.
  • Crude oil is a finite resource that is found in the Earth’s crust.
  • It is the remains of organisms that lived and died millions of years ago - mainly plankton, which was buried in mud.
  • Crude oil is a complex mixture of hydrocarbons.
  • Used as -   * Fuels such as petrol, diesel, kerosene, heavy fuel oil and liquefied petroleum gases   * Feedstock for the petrochemical industry   * Solvents   * Lubricants   * Detergents
  • A feedstock is a raw material used to provide reactants for an industrial reaction.
  • A petrochemical is a substance made from crude oil using chemical reactions.

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Alkanes:

  • Form a homologous series - A 'family' of organic compounds that have the same functional group and similar chemical properties. Alkanes:   * have the same general formula   * differ by CH2 in molecular formulae from neighbouring compounds   * show a gradual variation in physical properties, such as their boiling points   * have similar chemical properties
  • The general formula for the alkanes is CnH(2n+2), where n is the number of carbon atoms in the molecule.
  • Alkanes are saturated hydrocarbons:   * Hydrocarbons, because they are compounds containing hydrogen and carbon only   * Saturated, because their carbon atoms are joined by C-C single bonds

  \    Alkane Molecules

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