Using Resources Flashcards
What is a renewable energy source?
Sources of power that quickly replenish themselves and can be used again
What is a finite energy source?
Sources have a limited supply that will eventually run out
What is potable water?
Potable water is water that is safe for humans to drink. This means it contains a sufficiently low level of dissolved salts and microbes (so it is not pure)
How is rain water treated to turn it into potable water?
1) Water is passed through a mesh screen to remove large bits (twigs, stones)
2) Chemicals are added to make solids and microbes stick together to form sediment and sink.
3) Anaerobic digestion of sewage sludge
4) The water is then sterilized with chlorine to kill any microbes left.
How is salt water treated to turn it into potable water
If only sea water is available, desalination is required. This can be done through distillation or reverse osmosis however both are very expensive.
What is phytomining?
Phytomining uses plants to absorb metal compounds. The plants are harvested and then burned to produce ash that contains metal compounds.
What is bioleaching?
Bioleaching uses bacteria to produce leachate solutions that contain metal compounds.
What are life cycle assessments?
LCAs are carried out to assess the environmental impact of products in each of these stages:
• extracting and processing raw materials
• manufacturing and packaging
• use and operation during its lifetime
• disposal at the end of its useful life, including transport and distribution at each stage.
What is corrosion?
Corrosion is the destruction of materials by chemical reactions with substances in the environment. Rusting is an example of corrosion (air and water).
How can corrosion be prevented?
Corrosion can be prevented by applying a coating that acts as a barrier, such as greasing, painting or electroplating.
Explain sacrificial protection in terms of relative reactivity.
Some coatings are reactive and contain a more reactive metal to provide sacrificial protection. This works by the more reactive metal donating electrons to the other metal so that it doesn’t corrode.
E.g. Zinc is used to galvanise iron.
Why are alloys useful?
As most metals are too soft for everyday use and so are mixed with similar metals to make them harder.
What is bronze an alloy of?
Bronze is an alloy of copper and tin and is used in electrical connectors
What is brass an alloy of?
Brass is an alloy of copper and zinc and is used in tools
What is gold (in jewellery) an alloy of?
Gold used as jewellery is usually an alloy with silver, copper and zinc.
What is steel alloys of?
Steels are alloys of iron that contain specific amounts of carbon and other metals. High carbon steel is strong but brittle. Low carbon steel is softer and more easily shaped. Steels containing chromium and nickel (stainless steels) are hard and resistant to corrosion.
Explain how low density and high density poly(ethene) are both produced and what are their characteristics?
LD and HD poly(ethene) are both made under different reaction conditions with different catalysts. LD has weaker forces of attraction meaning it has a lower melting point and is soft. HD has higher forces of attraction giving it a higher melting point.
explain the difference between thermosoftening and
thermosetting polymers in terms of their structures.
Thermosoftening polymers are made of individual, tangled polymer chains that are easily separated and melted by heat. Thermosetting polymers consist of polymer chains that cross-link, so they do not melt when heated.
Give two examples of composites
Bricks and pottery
What is the Haber process?
The Haber process is used to make ammonia, which can be used to produce nitrogen-based fertilisers.
Nitrogen + Hydrogen Ammonia
How are the nitrogen and hydrogen sourced in the Haber Process?
Nitrogen is obtained from the air hydrogen can be obtained from natural gas
Describe the actual process itself?
The purified gases are passed over a catalyst of iron at a high temperature (about 450°C) and high pressure (about 200 atmospheres). Some of the hydrogen and nitrogen reacts to form ammonia. On cooling, the ammonia liquefies and is removed. The remaining
hydrogen and nitrogen are recycled.
What are NPK fertilizers?
NPK fertilizers are fertilizers containing compounds of nitrogen, phosphorus, and potassium and is used to improve agricultural productivity.
