Alkanes properties and combustion

• What are alkanes classified as in terms of their chemical structure?

  Alkanes are a homologous series of hydrocarbons containing only carbon and hydrogen atoms with no double bonds.
• What are the names of the first four alkanes in the series?

  Methane, ethane, propane, and butane.
• 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 (more than four carbons) are liquids at room temperature.
  • Very long alkanes can be solids.
• How does the volatility of alkanes change with chain length?

  Shorter alkanes are more volatile and evaporate more easily.
• What does it mean for an alkane to be viscous?

  Viscous means that the alkane is thick and sticky, like honey.
• Why are shorter alkanes more flammable?

  Shorter alkanes are easier to ignite or burn due to their low boiling points.
• What is the main use of hydrocarbons like alkanes?

  • They are used as fuel.
  • They release a large amount of energy when burned with oxygen.
• What is complete combustion of hydrocarbons?

  Complete combustion occurs when a hydrocarbon reacts with oxygen to form carbon dioxide and water, releasing energy.
• What type of reaction is combustion?

  Combustion is an exothermic reaction.
• What happens to hydrogen and carbon in hydrocarbons during combustion?

  They are oxidized by combining with oxygen to form carbon dioxide and water.
• What is the balanced equation for the complete combustion of propane (\(C_3H_8\))?

  \(C_3H_8 + 5O_2 \rightarrow 3CO_2 + 4H_2O\)
• How do you balance the combustion equation for nonane (\(C_9H_{20}\))?

  The balanced equation is \(C_9H_{20} + 14O_2 \rightarrow 9CO_2 + 10H_2O\).
• What are the key points to remember about the properties of hydrocarbons like alkanes?

  • Properties depend on the length of the carbon chain.
  • Shortest hydrocarbons have the lowest boiling points.
  • Short hydrocarbons are the most volatile and flammable.
  • Combustion of hydrocarbons produces carbon dioxide and water, releasing energy.
• What is required for complete combustion to occur?

  There must be enough oxygen available for the reaction.
• What are the products of complete combustion of hydrocarbons?

  The products are carbon dioxide and water.