C9 - Crude oil and fuels

• What is the primary source of important chemicals in the 21st century?

  Organic carbon compounds from crude oil
• Why are organic compounds significant in our lives?

  They are used for fuels and electricity generation
• What happens when oil prices rise?

  It affects the whole world economy
• What is crude oil?

  A finite resource found in rocks
• How is crude oil formed?

  From remains of ancient sea animals and plants
• What conditions are necessary for crude oil formation?

  High pressure and temperature, without oxygen
• What is the appearance of crude oil?

  A dark, smelly liquid
• What are hydrocarbons?

  Compounds containing only hydrogen and carbon
• What is the process used to separate mixtures of liquids?

  Distillation
• Why is crude oil not useful directly after extraction?

  It contains too many substances with different boiling points
• What are fractions in the context of crude oil?

  Substances with similar boiling points
• What is the general formula for alkanes?

  C_nH_2n+2
• What are alkanes described as?

  Saturated hydrocarbons
• What does it mean for alkanes to be saturated?

  They contain maximum hydrogen atoms in each molecule
• What are the first four alkane molecules?

  CH₄, C₂H₆, C₃H₈, C₄H₁₀
• How does the size of a hydrocarbon molecule affect its boiling point?

  Larger molecules have higher boiling points
• What is fractional distillation?

  A process to separate hydrocarbons with similar boiling points
• What happens to hydrocarbons with the smallest molecules during fractional distillation?

  They are piped out as gases
• What are the products of complete combustion of hydrocarbons?

  Carbon dioxide and water
• What is the chemical equation for the combustion of propane?

  C₃H₈ + 5O₂ → 3CO₂ + 4H₂O
• How can you test for water produced in combustion?

  Use cobalt chloride paper or copper sulfate
• What is incomplete combustion?

  Burning with insufficient oxygen
• What toxic gas is produced during incomplete combustion?

  Carbon monoxide
• Why is cracking important in the oil industry?

  It produces smaller, more useful hydrocarbons
• What is the process of cracking hydrocarbons?

  Breaking large hydrocarbons into smaller ones
• What type of hydrocarbons are produced from cracking?

  Saturated and unsaturated hydrocarbons
• How can you distinguish between alkenes and alkanes?

  Alkenes decolorize bromine water
• What is a positive test for an unsaturated hydrocarbon?

  Turns orange bromine water colorless
• What happens to the properties of hydrocarbons as chain length increases?

  Boiling point and viscosity increase
• What are lighter fractions from crude oil used for?

  As fuels
• Why do lighter fractions ignite more easily?

  They have lower boiling points
• What is the significance of the continuous process in fractional distillation?

  It allows for efficient collection of fractions
• What is the role of a fractionating column in distillation?

  To separate hydrocarbons by boiling points
• What happens to hydrocarbons with larger molecules during fractional distillation?

  They form thick liquids or solids
• What is the relationship between the size of hydrocarbon molecules and their properties?

  Properties depend on the size of molecules
• What is the main product of complete combustion of hydrocarbons?

  Carbon dioxide
• How can you test for carbon dioxide produced in combustion?

  Limewater turns cloudy
• What is the effect of incomplete combustion on health?

  Produces toxic carbon monoxide
• What is the significance of the double bond in alkenes?

  It makes them more reactive than alkanes
• What is the result of adding bromine water to an alkene?

  Turns bromine water colorless