cracking

• Why do heavy fractions of crude oil not make good fuels?

  They don't ignite easily
• What is a characteristic of heavy fractions of crude oil?

  They have high boiling points
• What is another reason heavy fractions of crude oil are poor fuels?

  They have low volatility
• What is cracking in the context of hydrocarbons?

  • Process that breaks down long-chain hydrocarbons
  • Produces shorter-chain, more useful molecules
  • Example of thermal decomposition reaction
• What is one method of cracking hydrocarbons?

  Catalytic cracking
• How is catalytic cracking performed?

  Vapourised heavy hydrocarbons pass over a hot catalyst
• What products are formed from catalytic cracking?

  Alkanes and alkenes
• What is another method of cracking hydrocarbons?

  Steam cracking
• How is steam cracking performed?

  Vapourised heavy hydrocarbons mixed with steam
• What products are formed from steam cracking?

  Alkanes and alkenes