Organic Chemistry

• what type of resource is crude oil

  finite
• where is crude oil found

  in rocks
• what formed crude oil

  from the remains of an ancient biomass consisting of mainly plankton that was buried in mud
• what is crude oil

  a mixture of a very large number of compounds which are mostly hydrocarbons
• what is a hydrocarbon

  a substance made up of hydrogen and carbon only
• what type of hydrocarbons are found in crude oil

  alkanes
• what is the general formula of an alkane

  CnH2n+2
• what is an homologous series

  • have same general formula
  • differ by CH2
  • have similar chemical properties
  • show a gradual change in physical properties (e.g. boiling points)
• what are the first four alkanes

  methane, ethane, propane, butane
• how can alkanes be represented

  molecular formula e.g. C2H6, displayed formula
• how is crude oil separated into its fractions

  fractional distillation
• what two processes are involved in fractional distillation

  evaporation and condensation
• what is a fraction

  a mixture containing molecules with a similar number carbon atoms
• what are fractions used to produce

  fuels and feedstock for the petrochemical industry
• some products from the petrochemical industry

  • solvents
  • lubricants
  • polymers
  • detergents
• why are there a vast array of natural and synthetic carbon compounds produced from fractional distillation of crude oil

  the ability of the carbon atoms to form families of similar compounds
• name some properties dictated by the size of a hydrocarbon

  • boiling point
  • viscosity
  • flammability
• what are the trends in the properties of alkanes

  as molecular size increases boiling point increases, viscosity increases, flammability decreases
• what is released during the combustion of a hydrocarbon

  energy
• what happens to the carbon and hydrogen when a hydrocarbon is burnt (combustion)

  they are oxidised
• what is produced during the complete combustion of a hydrocarbon (fuel)

  carbon dioxide and water
• write an equation for the combustion of propane

  propane + oxygen --> carbon dioxide + water
• how are hydrocarbons broken down into smaller more useful molecules

  cracking
• why are hydrocarbons cracked

  to meet demand for high demand products such as fuels
• what are the two types of cracking

  catalytic and steam
• what are the conditions for catalytic cracking

  temperature of 550⁰C, zeolite catalyst

  (is made up from aluminium oxide and silicon oxide)
• what are the conditions for steam cracking

  higher temperature than catalytic cracking and no catalyst
• what type of hydrocarbon is formed during cracking

  alkenes
• which type of hydrocarbon is more reactive

  alkenes
• what is the test for an alkene

  bromine water, goes orange to colourless
• what is produced from alkenes

  polymers and starting materials for the production of many other chemicals
• name some fractions produced from crude oil

  • petrol
  • diesel oil
  • kerosene
  • heavy fuel oil
  • liquefied petroleum gases (LPG)
• what is found at the top of the fractionating column?

  short chain fractions, with low boiling points (due to weak intermolecular forces) and high volatility are found
• what do the properties of hydrocarbons influence

  how the hydrocarbon is used as a fuel
• Is the molecule above a hydrocarbon?

  Yes

  
• Which Alkane is shown above?

  Ethane

  
• Which Alkane is shown above?

  Butane

  
• Name the hydrocarbons A to C on the diagram above?

  A) LPG

  B) Petrol

  C) Bitumen

  
• Are short-chain fractions more or less volatile?

  more
• What does cracking produce?

  A short alkane and an alkene