test

• compare how easily potable water can be obtained from:

  waste water and ground water

  potable water is more easier to obtain from ground water since it takes less time to purify and it requires fewer processes. This is because ground water is filtered to remove particles which are insoluble, then it is sterilised using chlorine to kill bacteria. this produces potable water.
• compare how easily potable water can be obtained from:

  waste water and ground water

  However waste water is harder to obtain from the ground since it requires more processes of treatment. Waste water goes through screening and grit removal to remove solids. Sedimentation separates solid waste producing sewage sludge which is anaerobically digested by bacteria. this is then sterilised using chlorine to produce potable water
• explain why one product of cracking is high in demand

  its a small molecule so its more flammable and can be used as a fuel
• Describe how coal was formed from the carbon dioxide in the early earths atmosphere?

  Coal was formed from dead organisms/plants due to the high amounts of carbon dioxide used in photosynthesis. These organisms fell towards the sea bed and was buried and compressed in layers of sediment over millions of years to form coal
• describe how bio leaching is used to extract copper from low grade ores.

  this uses bacteria which carry out a chemical reaction that produces leachate solutions then copper is displaced through electrolysis
• Describe how a reversible chemical reaction is able to reach equilibrium

  when the forwards and reverse reactions have the same rate in a closed system
• Le Chateliers Principle

  the effects of changing conditions on the position or an equilibrium
• The amount of nitrogen increased because of the emissions from volcanoes

  the amount of Oxygen increased due to the evolution of algae and green plants which lead to photosynthesis