Hydro carbons

• What is a homologous series?

  A series with the same general formula
• How do compounds in a homologous series differ?

  They differ by a CH$_2$ unit
• What physical property variation is shown in a homologous series?

  Gradual variation in physical properties
• What is the general formula for alkanes?

  • C_nH_2n+2
• What is the chemical formula for methane?

  CH₄
• What is the structure formula for ethane?

  1. C-C-H
• What is the chemical formula for propane?

  C₃H₈
• What is the structure formula for butane?

  1. C-C-C-C-H
• What are isomers?

  Same molecular formula, different arrangements
• What is the bonding in simple molecular structures?

  • Weak intermolecular forces
  • Simple molecular structure
• What is crude oil?

  A complex mixture of hydrocarbons
• What are the two main sources of crude oil?

  Fuels and feedstock for petrochemical industry
• Why is crude oil considered finite?

  It is made very slowly and limited
• What does non-renewable mean in the context of crude oil?

  It will run out as supply cannot be renewed
• What are the products of complete combustion of hydrocarbons?

  • Carbon dioxide (CO₂)
  • Water (H₂O)
• What is produced during incomplete combustion?

  Carbon monoxide and soot
• What happens to vapours that do not condense in fractional distillation?

  They are collected as gases at the top
• What is fractional distillation of crude oil?

  • Heating crude oil
  • Vapours rise in a fractionating column
  • Fractions condense at different heights
• What are the characteristics of fractions obtained from fractional distillation?

  • Simpler, more useful mixtures
  • Similar numbers of carbon atoms
  • Small range of boiling points
• What is the boiling point trend in alkanes?

  Increases with the number of carbon atoms
• What is the significance of increasing carbon atoms in alkanes?

  Increases boiling point and ignition power
• How does the structure of hydrocarbons affect their properties?

  More carbon atoms lead to higher boiling points
• What is the chemical equation for complete combustion of alkanes?

  Alkane + O₂ → CO₂ + H₂O
• What is the role of intermolecular forces in hydrocarbons?

  They determine the physical properties of hydrocarbons
• What is the formula for the combustion of methane?

  CH₄ + 2O₂ → CO₂ + 2H₂O
• What is kerosene used for?

  Fuel for aircraft
• How does the strength of intermolecular forces change with increasing carbon atoms?

  Strength increases with more carbon atoms
• What is the main use of bitumen?

  Surface for roads and roofs
• What is diesel oil used for?

  Fuel for some cars and trains
• What is fuel oil used for?

  Fuel for large ships and power stations
• What is the use of petrol?

  Fuel for cars
• What is the use of gases obtained from crude oil?

  Domestic heating
• What is the use of fuel oil?

  Fuel for large ships and power stations
• What is the use of bitumen?

  Surface for roads and roofs
• What is the use of kerosene?

  Fuel for aircraft
• What is the use of diesel oil?

  Fuel for some cars and trains