Distillation

• What is the main technique used to separate hydrocarbons in crude oil?

  Fractional distillation
• Why do longer chain hydrocarbons have higher boiling points than shorter chain hydrocarbons?

  Because they have greater molecular weight and stronger intermolecular forces
• What happens to crude oil when it is heated in fractional distillation?

  It boils and turns into gas
• How does the temperature gradient in the fractional distillation column affect the separation of hydrocarbons?

  Hotter at the bottom and cooler at the top allows for different boiling points to condense at various heights
• What occurs to hydrocarbon vapors as they rise up the fractional distillation column?

  They condense back into liquid when they reach their boiling point
• Where are very long chain hydrocarbons removed from in the fractional distillation column?

  From the bottom of the column
• Where are very short chain hydrocarbons removed from in the fractional distillation column?

  From the top of the column as gases
• What are the functions of the important fractions produced by fractional distillation?

  • Petrol: used as fuel for cars
  • Diesel: used as fuel for cars
  • Kerosene: used as jet fuel
  • Heavy fuel oil: used to power ships
  • Liquefied petroleum gas: used in camping stoves
• What is meant by the term 'feed stock' in the context of the petrochemical industry?

  • A chemical used to make other chemicals
  • Examples include solvents, lubricants, detergents, and polymers
• What is a common use for kerosene?

  It is used as jet fuel
• What is a common use for heavy fuel oil?

  It is used to power ships
• What is a common use for liquefied petroleum gas?


  It is used in camping stoves
• Why is it important to learn the stages of fractional distillation?

  Because it often comes up in exam questions
• What type of hydrocarbons do fractions produced by fractional distillation contain?

  Hydrocarbons with a similar number of carbon atoms