C8-fuels and earth science

• hydrocarbons are Compunds that contain hydrogen and carbon atoms only
• crude oil is a mixture of hydrocarbons
• fractional distallation is used to seperate crude oil
• What are gases from crude oil used for?

  domestic heating and cooking

  What is petrol used for?

  fuel for cars

  What is kerosene used for?

  fuel for aircraft

  What is diesel oil used for?

  fuel for some cars and trains

  What is fuel oil used for?

  fuel for large ships and in some power stations What is bitumen used for?

  to surface roads and roofs
• fractions from fractional distillation of

  crude oil from the top to the bottom of the column

  gases, petrol, kerosene, diesel oil, fuel oil, bitumen
• general formula of alkanes?

  CnH2n+2
• complete combustion: oxygen + fuel -> carbon dioxide + water
• incomplete combustion of a fuel produces carbon monoxide and water
• sulfur dioxide dissolves in rain water to give acid rain
• oxygen and nitrogen reacts in engines to produce nitrogen oxide
• cracking is the process to break down longer chain saturated hydrocarbons into smaller useful ones
• gasses produces by volcanic acitivity made the early atmosphere
• co2 was the main component of the early atmosphere
• oceans were formed by the condesation of water vapour
• primitive plants photosynthesised to increase the amount of o2 in the atmosphere
• chemical test for 02-glowing splint relights
• CO2 AND CH4 AND water vapour are green house gases
• viscosity

  shorter hydrocarbons=less

  longer hydrocarbons=more
• shorter hydrocarbons =more flammable and easier to ignite
• homologous series

  Have the same general formula

  Differ by CH2 in molecular formulae from neighbouring compounds

  Show a gradual variation in physical properties, as exemplified by their boiling points

  Have similar chemical properties
• what is dangerous about carbon monoxide

  colourless and odourless

  diffuses into bloodstream and binds to haemogoblin which stops 02 being sent around the body
• Soot can block pipes carrying waste gases away

  from an appliance, cause breathing problems if inhaled and blacken buildings
• Give disadvantages of using hydrogen as a fuel in cars

  • Hydrogen is a gas at room temperature and so is difficult to store in large amounts unless it is compressed or cooled so that it becomes a liquid
• alkenes are unsaturated hydrocarbons

  CnH2n