Alkanes- properties and combustion

• What are alkanes a series of?

  Hydrocarbons
• What do alkanes contain only?

  Carbons and hydrogen atoms
• What type of bonds do alkanes not have?

  Double bonds
• How many alkanes were covered in the video?

  Four
• What happens to the boiling point of alkanes as the carbon chain length increases?

  It increases
• What state do the first four alkanes exist in at room temperature?

  Gases
• What state are longer alkanes with more than four carbons at room temperature?

  Liquids
• What can happen to very long alkanes at room temperature?

  They can be solid
• Why are shorter alkanes more volatile?

  They have lower boiling points
• What does it mean for longer alkanes to be more viscous?

  They are thick and sticky
• Why are shorter alkanes more flammable?

  They ignite more easily
• What is one main use of hydrocarbons like alkanes?

  Fuel
• What happens during complete combustion of hydrocarbons?

  They react with oxygen to release energy
• What are the products of complete combustion of hydrocarbons?

  Carbon dioxide and water
• What type of reaction is complete combustion?

  Exothermic reaction
• What happens to hydrogen and carbon in hydrocarbons during combustion?

  They are oxidized
• What is the molecular formula of propane?

  C₃H₈
• What is the balanced equation for the complete combustion of propane?

  C₃H₈ + 5O₂ → 3CO₂ + 4H₂O
• What is the molecular formula of nonane?

  C₉H₂₀
• What is the balanced equation for the combustion of nonane?

  C₉H₂₀ + 14O₂ → 9CO₂ + 10H₂O
• What are the properties of alkanes related to their carbon chain length?

  • Boiling point increases with chain length
  • Shorter alkanes are gases at room temperature
  • Longer alkanes are liquids or solids
  • Shorter alkanes are more volatile
  • Longer alkanes are more viscous
  • Shorter alkanes are more flammable
• What is the process of combustion in hydrocarbons?

  • Hydrocarbon reacts with oxygen
  • Produces carbon dioxide and water
  • Releases energy (exothermic reaction)
  • Requires sufficient oxygen for complete combustion
• What is the key takeaway about hydrocarbons like alkanes?

  • Properties depend on carbon chain length
  • Shortest hydrocarbons are most volatile and flammable
  • Combustion produces energy, CO₂, and H₂O