C2 - Chemical Patterns

• Crude oil is formed from the buried remains of plants and animals (so is a fossil fuel)
• Refined petroleum products are used as fuels, lubricants, solvents, plastics, etc.
• Crude oil is a mixture of different hydrocarbons. It is mainly made up of fractions of alkanes(Cn H2n+2) and alkenes(Cn H2n)
• Fractional distillation separates crude oil into its components based on their boiling points
• The boiling point increases with increasing molecular mass
• The longer hydrocarbons have high boiling points due to having a longer chain length thus more atoms and stronger intermolecular forces and covalent bonds so more energy is needed for them to break
• The shorter hydrocarbons have lower boiling pointa due to them having a shorter chain length so less atoms meaning less covalent bonds and weaker intermolecular forces meaning less energy is needed to break them
• A life-cycle assessment (LCA) looks at each stage of life of a product and works out the potentional environmental impact of each stage and the product
• There are 4 stages to a life-cycle assesment

  1. Materials and manufacturing
  2. Transport
  3. Product use
  4. Disposal