Combustion of Alkanes

• Condition needed for complete combustion?

  When fuel is burnt plentiful supply of oxygen
• Product formed from complete combustion?

  Carbon dioxide and Water
• Chemical test for water

  1. Anhydrous copper sulphate turns from white to blue
  2. Cobalt chloride paper turns blue to pink
• Physical test for water?

  Boiling point of 100°C
• Chemical test for carbon dioxide?

  1. Bubble gas through limewater
  2. A white precipitate forms (turns cloudy)
• Why is the production of carbon dioxide harmful?

  They are greenhouse gasses which contribute to global climate change
• How is Carbon Monoxide formed?

  When hydrocarbons burns in an insufficient supply of oxygen

  Incomplete combustion
• Negative impact of carbon monoxide?

  • Global dimming
  • Colourless odorless and tasteless
  • It is a toxic gas - replaces oxygen in the blood and causes poisoning by oxygen deficiency
• How are particulates formed?

  Burning: soot, smog
• Negative impact of particulates?

  Causes global dimming and health problems
• How does sulphur dioxide form?

  Compounds containing small quantities of sulphur are heated in the air and form SO2

  SO2 + H2O -> H2SO3
• Negative impacts of sulphur dioxide?

  • Causes acid rain
  • It is toxic
• How is nitrogen oxide produced?

  When high pressure and temperature in car engines cause Nitrogen and oxygen to react:

  4N02(g) + O2(g) -> 2H20(g) + 4HNO3(g)
• Negative impacts of nitrogen oxides?

  • Toxic gas
  • Harmful to environment - acid rain
• How are unburnt hydrocarbons formed?

  • Fuels pass through car engines without combusting
  • Released at petrol filling stations
• Negative impacts of unburnt hydrocarbons?

  • Global dimming
  • Respiratory irritant
• What do catalytic converters do?

  Convert toxic harmful gases to less harmful gases
• What does the honeycomb structure contain and provide?

  • A larger surface are
  • Contains transition metals - Platinum Palladium Rhodium which are the catalysis
• Carbon monoxide reacts with oxygen to make carbon dioxide
• Nitrogen oxide reacts to make Oxygen and Nitrogen
• Equation for catalytic converters

  2CO + 2NO -> 2CO2 + N2
• What is flue gas desulphurisation?

  Process of removing sulfur dioxide from flue gases emitted by power stations.
• What are the 2 methods for removing sulphur dioxide?

  1. Slurry of calcium oxide and water
  2. Slurry of calcium carbonate and water
• Equations for flue gas desulphurisation on anki
• What is produced with both methods of flue gas desulfurisation?

  Gypsum
• What is gypsum used for?

  A saleable product used to make builder' plaster and plasterboard