Alkanes as Fuels

• What are alkanes primarily found in?

  Fossil fuels
• Why are alkanes considered great fuels?

  They release a large amount of energy
• In what systems are alkanes commonly burnt?

  Power stations and car engines
• What is produced during complete combustion of alkanes?

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

  C₃H₈(g) + 5O₂(g) → 3CO₂(g) + 4H₂O(g)
• What happens during incomplete combustion of hydrocarbons?

  Produces soot and carbon monoxide
• What is the equation for the incomplete combustion of propane?

  C₃H₈(g) + 3½O₂(g) → 3CO(g) + 4H₂O(g)
• Why is carbon monoxide dangerous?

  It binds to haemoglobin, preventing oxygen transport
• How can carbon monoxide be removed from exhaust gases?

  Using catalytic converters
• What are the main pollutants from vehicle exhausts?

  Nitrogen oxides, unburnt hydrocarbons, carbon monoxide
• What is the general formula for nitrogen oxides?

  NOₓ
• How is nitrogen monoxide produced in car engines?

  From high pressure and temperature reactions
• What is the reaction to produce nitrogen dioxide from nitrogen monoxide?

  2NO(g) + O₂(g) → 2NO₂(g)
• What is ground-level ozone and how is it formed?

  It forms from unburnt hydrocarbons and nitrogen oxides
• What are the effects of ground-level ozone on health?

  It irritates eyes and aggravates respiratory issues
• What is the process that converts sulfur into sulfur dioxide when fossil fuels are burnt?

  Combustion of sulfur in fossil fuels
• What is produced when sulfur dioxide dissolves in moisture?

  Sulfuric acid
• What is acid rain and what causes it?

  Rain containing sulfuric and nitric acids
• What are the environmental impacts of acid rain?

  Destroys vegetation and corrodes buildings
• How can sulfur dioxide be removed from power station flue gases?

  By reacting with alkaline slurry
• What is the reaction that forms calcium sulfite from sulfur dioxide?

  CaO(s) + SO₂(g) → CaSO₃(s)
• What is the greenhouse effect?

  Greenhouse gases absorb and emit infrared energy
• How does burning fossil fuels contribute to global warming?

  It increases carbon dioxide levels in the atmosphere
• What are the main types of combustion of alkanes?

  • Complete combustion: Produces CO₂ and H₂O
  • Incomplete combustion: Produces CO, soot, and CO₂
• What are the pollutants produced from burning fossil fuels?

  • Carbon monoxide
  • Nitrogen oxides
  • Unburnt hydrocarbons
  • Sulfur dioxide
• What are the environmental effects of pollutants from combustion?

  • Ground-level ozone formation
  • Acid rain production
  • Health issues from pollutants
• What is the role of catalytic converters in vehicles?

  • Remove pollutants from exhaust gases
  • Convert harmful gases into less harmful substances