Using Resources

Question 1

What do Humans use the Earth’s resources for?

Answer 1

Humans use the Earth’s resources to provide warmth, shelter, food and transport.

Question 2

What do Natural Resources provide?

Answer 2

Natural resources, supplemented by agriculture, provide food, timber, clothing and fuels.

Question 3

What do Finite resouces from the Earth provide?

Answer 3

Finite resources from the Earth, oceans and atmosphere are processed to provide energy and materials.

Question 4

State conditions for drinkable water.

Answer 4

For humans, drinking water should have sufficiently low levels of dissolved salts and microbes.

Question 5

Define Potable Water.

Answer 5

Water that is safe to drink is called potable water.

Question 6

Why is potable water not pure water.

Answer 6

Potable water is not pure water in the chemical sense because it contains dissolved substances.

Question 7

Describe the production of fresh water in the UK.

Answer 7

In the United Kingdom (UK), rain provides water with low levels of dissolved substances (fresh water) that collects in the ground and in lakes and rivers.

Question 8

What does production of potable water depend on?

Answer 8

The methods used to produce potable water depend on available supplies of water and local conditions.

Question 9

Describe the production of potable water.

Answer 9

Most potable water is produced by: • choosing an appropriate source of fresh water
• passing the water through filter beds
• sterilising. Sterilising agents used for potable water include chlorine, ozone or ultraviolet light.

Question 10

Explain what happens when fresh water was limited.

Answer 10

If supplies of fresh water are limited, desalination of salty water or sea water may be required.

Question 11

Define Desalination.

Answer 11

• Desalination is the process by which the dissolved mineral salts in water are removed
• Desalination can be done by distillation or by processes that use membranes such as reverse osmosis. These processes require large amounts of energy.

Question 12

State a disadvantage of urban lifestyle.

Answer 12

Urban lifestyles and industrial processes produce large amounts of waste water that require treatment before being released into the environment.

Question 13

What does tge treatment of waste water need to do

Answer 13

• Sewage and agricultural waste water require removal of organic matter and harmful microbes.
• Industrial waste water may require removal of organic matter and harmful chemicals.

Question 14

Describe the treatment of sewage treatment.

Answer 14

Sewage treatment includes:
• screening and grit removal
• sedimentation to produce sewage sludge and effluent
• anaerobic digestion of sewage sludge
• aerobic biological treatment of effluent.

Question 15

Describe the amount of metal ores on Earth.

Answer 15

The Earth’s resources of metal ores are limited.

Question 16

2 new methods of extraction

Answer 16

phytomining, and bioleaching. These methods avoid traditional mining methods of digging, moving and disposing of large amounts of rock.

Question 17

Describe Phytomining.

Answer 17

Phytomining uses plants to absorb metal compounds. The plants are harvested and then burned to produce ash that contains metal compounds.

Question 18

Describe Bioleaching.

Answer 18

Bioleaching uses bacteria to produce leachate solutions that contain metal compounds.

The metal compounds can be processed to obtain the metal. Copper can be obtained from solutions of copper compounds by displacement using scrap iron or by electrolysis.

Question 19

Explain the Life Cycle Assessments.

Answer 19

• 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.

Question 20

What types of resources can be quantified.

Answer 20

Use of water, resources, energy sources and production of some wastes can be fairly easily quantified.

Question 21

Why is LCA not a objective process?

Answer 21

Allocating numerical values to pollutant effects is less straightforward and requires value judgements, so LCA is not a purely objective process.

Question 22

How can LCAs be used to evaluate a process.

Answer 22

Selective or abbreviated LCAs can be devised to evaluate a product but these can be misused to reach pre-determined conclusions, eg in support of claims for advertising purposes.

Question 23

How can we reduce the use if limited resources?

Answer 23

The reduction in use, reuse and recycling of materials by end users reduces the use of limited resources, use of energy sources, waste and environmental impacts.

Question 24

Sustainable development

Answer 24

Development that meets the needs of current generations without compromising the ability of future generations to meet their own needs

Question 25

Sterilising agents for potable water

Answer 25

Sterilising agents used for potable water include chlorine, ozone or ultraviolet light.

• Chlorine is a toxic gas so the amount added to water has to be carefully monitored.

• Using ultraviolet light to kill microbes avoids adding chemicals to the water but is more expensive

Question 26

Reverse osmosis

Answer 26

Sea water is passed through a membrane that only allows through the water molecules. It needs high pressure to push the water through the membrane. The high pressure requires a lot of energy to produce.

Question 27

Pros and cons of new extraction methods

Answer 27

These methods need less energy than traditional methods, and can work on low concentration ores but are slow to carry out.

Question 28

Pros and cons of recycling

Answer 28

Advantages of recycling:
- less acid rain (pollution)
- metal ore reserves last longer / conserved energy for extraction saved less mining / quarrying less waste less landfill creates local employment

Disadvantages of recycling;

• collection problems
• transport problems/ cost of transport
• difficult to separate metal from appliances/sort

Question 29

What is corrosion

Answer 29

Corrosion is the destruction of materials by chemical reactions with substances in the environment, e.g. rusting.

Question 30

How is corrosion prevented

Answer 30

Corrosion can be prevented by applying a coating that acts as a barrier, such as greasing, painting or electroplating. These methods stop the air or water coming into contact with the metal.

Question 31

Sacrificial protection

Answer 31

Some coatings are reactive and may contain corrosion inhibitors or a more reactive metal.
If two metals are in contact the more reactive metal will corrode instead of the less reactive one, e.g. zinc is used to galvanise iron and when scratched, provides sacrificial protection because zinc is more reactive than iron.

Question 32

Bronze

Answer 32

Bronze - an alloy of copper and tin, used for making statues and decorative objects.

Question 33

Brass

Answer 33

Brass - an alloy of copper and zinc used for producing water taps and door fittings.

Question 34

Gold

Answer 34

Gold used as jewellery is usually an alloy with silver, copper and zinc (The proportion of gold in the alloy is measured in carats, with pure gold being 24 carat)

Question 35

Aluminium magnesium

Answer 35

Aluminium-magnesium alloys are low density and used in aerospace manufacturing.

Question 36

Steel

Answer 36

Steels - 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

Question 37

How are properties of polymers determined

Answer 37

The properties of polymers depend on what monomers they are made from and the conditions under which they are made. For example, low density (LD) and high density (HD) poly(ethene) are produced from ethene, using different catalysts and reaction conditions.

Question 38

Thermosetting polymers

Answer 38

Thermosetting polymers do not melt on heating. The polymer molecules are linked to each other by strong cross-links.

Question 39

Thermosoftening polymers

Answer 39

Thermosoftening polymers soften easily on heating and can then be remoulded, keeping the new shape on cooling. The polymer molecules are attracted to each other by weak intermolecular forces.

Question 40

How is glass made

Answer 40

Most of the glass we use is soda-lime glass, made by heating a mixture of sand, sodium carbonate and limestone.

Borosilicate glass, made from sand and boron trioxide, melts at higher temperatures than soda-lime glass

Question 41

How are clay ceramics made

Answer 41

Clay ceramics, including pottery and bricks, are made by shaping wet clay and then heating in a furnace.

Question 42

Composites

Answer 42

Fibres or fragments of one material (reinforcement) are surrounded by a binder/matrix material that holds these fibres/fragments together.
E.g. fibreglass - glass fires bound together in a polymer, used for making storage tanks.

Question 43

Steps of the habour process

Answer 43

a) The purified Hy and Ny gases are passed over Fe catalyst at a high temperature (about 450 °C) and a high pressure (about 200 atm)

b)Fe speeds up the rate of reaction, so that a lower temperature could be used in the process.

C)Some of the hydrogen and nitrogen reacts to form ammonia. N, + 3 H, ~ 2 NH,

d)The reaction is reversible so ammonia breaks down again into nitrogen and hydrogen.

e)On cooling, the ammonia liquefies and is removed. The remaining hydrogen and nitrogen are recycled. This means almost no material is wasted.

f) Ammonia is used for production of nitrogen-containing fertilisers.

Question 44

Explain the compromises in the habour process

Answer 44

The conditions are a compromise between rate and the yield:

• The reaction is exothermic. An optimum temperature of 450 °C is used. Using a lower temperature would give a higher yield, but the rate of NH, production would be too slow.

• A pressure of 200 atm is used. Using a higher pressure would give a higher yield, but would be too expensive, because of the cost of energy to produce the high pressure.

Question 45

How are compounds of nitrogen phosphorus abd potassium used

Answer 45

Compounds of nitrogen, phosphorus and potassium are used as fertilisers to improve agricultural productivity. NPK fertilisers contain compounds of all three elements

Question 46

How is phosphate rock used in the production of fertilisers

Answer 46

• Phosphate rock is reacted with nitric acid to produce phosphoric acid and calcium nitrate.

• Phosphate rock can be reacted with sulfuric acid to produce a mixture of calcium phosphate and calcium sulfate

• Phosphate rock can be reacted with phosphoric acid to produce calcium phosphate.