Topic 8 fuels and earth science

• What is crude oil primarily composed of?

  Mixture of hydrocarbons
• What are hydrocarbons?

  Compounds containing only hydrogen and carbon
• What is the physical state of crude oil?

  Thick, sticky, black liquid
• Where is crude oil typically found?

  In porous rock underground and under the sea
• What is the structure of hydrocarbon molecules in crude oil?

  Carbon backbone with hydrogen atoms attached
• What does the mixture of crude oil contain?

  Molecules with different ring sizes and chain lengths
• What is crude oil used to produce?

  Fuels like petrol and diesel
• What is feedstock in the petrochemical industry?

  Raw materials derived from crude oil
• How is crude oil formed?

  From remains of plants and animals under pressure
• Why is crude oil considered a finite resource?

  It is used faster than it is formed
• What are some products obtained from crude oil?

  Polymers, lubricants, solvents, detergents, adhesives
• What is fractional distillation?

  A process to separate hydrocarbons in crude oil

  
• What do the fractions in petroleum consist of?

  Groups of hydrocarbons with similar chain lengths
• What determines the boiling points of hydrocarbons?

  The number of carbon atoms in the chain

  
• How does the size of a hydrocarbon molecule affect its fraction?

  Larger molecules are collected lower in the column
• What is the main component of most fractions from crude oil?

  Mainly alkanes with single bonds
• What is the temperature gradient in a fractionating column?

  Hot at the bottom, cool at the top
• What happens to vapours of hydrocarbons with high boiling points?

  They condense into liquid lower down
• Where are smaller hydrocarbons collected in the fractionating column?

  At the top as gases
• What are the main fractions obtained from crude oil?

  Refinery gases, gasoline, kerosene, diesel, fuel oil, bitumen

  
• What influences the properties of hydrocarbons?

  Size of their molecules
• How does boiling point change with molecular size?

  Boiling point increases with larger molecules
• What does viscosity refer to?

  Ease of flow of a liquid
• How does viscosity change with chain length?

  Viscosity increases with increasing chain length
• Why are higher alkanes useful as lubricants?

  They are less likely to burn and reduce friction
• How does molecular size affect ease of ignition?

  Smaller molecules are more flammable and easier to ignite
• What is a homologous series?

  Groups of organic compounds with similar features
• What is the difference in molecular formula between members of a homologous series?

  CH
• What trend is observed in the boiling points of alkanes?

  Boiling points increase with larger molecules

  
• What is the major source of atmospheric pollution?

  Combustion of fossil fuels
• What are fossil fuels?

  Coal, oil, natural gas, oil shales, tar sands
• What are the products of complete combustion of hydrocarbons?

  Water and carbon dioxide
• What occurs during incomplete combustion?

  Insufficient oxygen leads to unburnt fuel and carbon monoxide
• What is carbon monoxide?

  Toxic and odourless gas
• How does carbon monoxide affect the body?

  It binds to haemoglobin, preventing oxygen transport

  
• What should you be able to predict regarding combustion products?

  Based on fuel composition and conditions
• What is the significance of the high affinity of CO to haemoglobin?

  It prevents binding of oxygen and carbon dioxide

  
• What is produced during incomplete combustion?

  Unburnt fuel, carbon monoxide, and water
• What happens to methane in an oxygen-poor environment?

  It undergoes incomplete combustion
• What is carbon monoxide?

  A toxic and odourless gas