Paper 2- Unit 10 Using Earth's resources and potable water Flashcards
What are finite resources?
materials that will run out
Name 2 finite resources
Fossil fuels
metal ores
What is potable water?
Water with low levels of dissolved salts
and ionsq
How is lake water treated?
Choose appropriate water source
pass water through filter beds
sterilisation of water
Why is lake water filtered?
to remove solid waste
such as stones, leaves, branches
Why is lake water sterilised
lake water contains microbes
water is sterilised to kill harmful microbes
Name 3 sterilising agents
Ozone
Chlorine
ultra violet light
What is desalination?
When potable water is produced from
salt water (from the ocean)
Describe how salt water can be distilled to produce pure water
Salt water is heated
water vapour is produced
water vapour is cooled and condensed`
What is the difference between potable water and pure water
potable water contains low levels of ions
pure water only contains water molecules
How can you test water to see if it is pure?
pure water boils at 100 degrees
impure boils at a lower temperature (over a range)
take a salt and evaporate all the water off
check if any salt is left behind
What is reverse osmosis?
When water is forced
through a semi permeable membrane
to produce pure water
Steps for waste water treatment
1) Screening/grit removal
2) sedimentation to produce water sludge
3) anerobic digestion of sludge `
4) areobic respiration of effluent (solution)
Phytomining is…
when plants absorb metal compounds from soil
plants are burnt
metal obtained from plant ash
Bioleaching is…
when bacteria ‘feed’ on low grade ore
to produce a leachate (solution)
metal is extracted
Why is scrap iron used to displace copper from copper sulphate
Iron is more reactive than copper
scrap iron is used to save resources
iron is a finite resources
cheap than extraction
How can you extract copper from copper sulphate?
scrap iron can displace the copper
electrolysis
Explain why electrolysis of copper sulphate is expensive
Lots of energy needed
costs money
4 steps involved in a life cycle assessment
Extraction and processing of raw material
manufacturing and packaging
Use and operation during life time
disposal at the end of useful life i.e. transport and distribution
Pros of recycling
Limited raw materials (finite)
costs less money to recycle then make new material
3 ways of reducing the use of resources
Recycling
Reducing the use
Reusing
How can metals be recycled?
Metal is melted
then recasted
Example of metal recycling
Scrap steel can be used in the blast furnace
to produce new iron
Word equation for the reduction of iron
Iron oxide + carbon –>
Word equation for the reduction of iron
Iron oxide + carbon –> Iron + carbon dioxide
