C12 - chem

• Whats finite resource mean?

  cannot be formed quick enough to consider replaceable.
• whats renewable energy mean?

  can be reformed at a similar rate or faster than we use them
• What are natural resources?

  • Anything that comes out of the sea, land, air is a natural resource
  • We use natural resources to make energy and materials
• What are synthetic products ?

  • man made products
  • naturally occurring polymers extracting rubber from trees
  • synthetic products are manufactured using chemical reactions
• Why do we need synthetic products?

  • Natural resources are finite
  • some people are concerned about maintaining natural resources for future generations
  • some synthetic products are better than natural ones
• What are the risks of extracting finite resources?

  • negative health issues
  • negative environmental issues
  • lack of sustainability
• Why do plastic bottles impact the environment?

  • Requires lots of energy
  • transporting the plastic used fossil fuels
  • not biodegradable so causes litter issues
  • some end up in oceans causing wildlife issues
• Reuse decrease advantages

  • Saves energy
  • less global warming
• Reuse decrease disadvantages

  • Could cause littering
  • could still be sent to landfills
• Recycle increase advantage

  • Saves crude oil
  • cuts down on CO2 emissions
• Recycle increase disadvantage

  • Collection point sites cause eyesores
  • causes litter issues
• Burning decrease advantages

  • Can provide energy for heating buildings and generating electricity
• Burning decrease disadvantages

  • Increases global warming
  • could release toxic gases
• what’s the life cycle assessment?

  A way of analysing the impact of manufactured products on the environment.
• what are the 4 stages of the LCA

  1. Extract and process raw materials
  2. manufacturing and processing
  3. use and reuse
  4. dispose
• what’s the 2 main ways of extracting metals from their ores?

  • Burning ores with carbon ( reduction and oxidation )
  • electrolysis
• How do you determine which method to use when extracting metals

  Use the reactivity series to compare how easily and how vigorous these metals react
• How do you determine which method to use when extracting metals ( potassium to aluminium)

  Metals above must be extracted using electrolysis
• How do you determine which method to use when extracting metals ( carbon to copper )

  metals less reactive than carbon can be extracted from their ores by reduction or oxidation using carbon
• How do you determine which method to use when extracting metals ( silver to gold)

  Platinum ,gold, silver and copper can occur natives and don’t need to be extracted
• What are the 2 types of Cu ores?

  1. Low grade Cu ores
  2. high grade Cu ores
• what’s an alternative method of extracting metals

  1: PYHTOMINING

  • Plants are grown on low grade ores
  • roots absorb metals containing compounds
  • they are harvested and burnt
  • ash contains metal compounds
• What’s the advantages and disadvantages of pythomining

  adv: plants can grow on contaminated low grade ore

  disad: metal produced isn’t pure which makes electrolysis need to be used
• what’s an alternative method of extracting metals

  2. BIOLEACHING

  • bacteria feed on low grade ores
  • they create a leachate solution
  • this solution contains metal compounds
• What’s the advantages and disadvantages of bioleaching

  adv: very energy sufficient

  disad: a very slow process
• What's the difference between potable and pure water ?

  • Pure water contains only water
  • Water that's drinkable is potable water
  • Potable water isn't pure because it contains dissolved substances
• Hows potable water produced ?

  Stage 1 : source the water

  stage 2 : filtration

  pass the water through a filter bed to remove insoluble substances

  stage 3 : sterilisation ( used to kill microorganisms)
• Desalination by reverse osmosis

  1. water puts under high pressure and passed through a membrane which has tiny pores in it
  2. the pores allow water molecules to enter
  3. prevents most ions and molecules from passing through
• Desalination by reverse osmosis advantages

  1. its safe method to use
  2. provides better water for cooking
  3. it filters the most contaminants
• Desalination by reverse osmosis disadvantages

  1. Requires lots of energy
  2. more waters wasted
  3. water waste requires proper disposal
• Desalination by distillation

  1. Sea water heated until it boils
  2. the salt remains in the liquid and the steam evaporates
  3. the steams cooled + condensed to make potable water
• Desalination by distillation advantages

  • Provides ppl w potable water ( clean and fresh )
  • provides water to the agricultural industry
• Desalination by distillation disadvantages

  • Requires lots of energy
  • many ppl don’t like the taste of pure water
• What substances r removed from waste water?

  1. Waste from homes and agriculture - harmful microbes
  2. industrial waste water- harmful chemicals
• What are the stages of treating waste water?

  1. The wastes screened to remove grit and debris
  2. sedimentation occurs which separates the sludge and effluent
  3. bacteria’s added to remaining water and O is bubbles to encourage aerobic digestion of organic matter
  4. Anaerobic digestion of the sludge takes place