Fractional distillation of crude oil

• explain how fractional distillation of crude oil takes place

  • crude oil is heated and vaporised
  • vapor rises up the fractionating column
  • column is hotter at bottom
  • hydrocarbons cool as they go up the column and condense at different heights as they have different boiling points
  • large molecules, high boiling points, collected at bottom
  • this gives fractions which can be used in various ways