Topic 10: Using Resources Flashcards
What are the 2 main groups of ceramics?
- Clay ceramics
- Glass
What makes clay ideal for making pottery and bricks?
Its ability to be moulded when wet and then hardened
What is most glass made from?
Soda-lime glass
What is soda-lime glass composed of? [3]
- Limestone
- Sand
- Sodium carbonate (soda)
What is different about borosilicate glass?
Has a higher melting point than soda-lime glass
What is borosilicate glass composed of? [2]
- Sand
- Boron trioxide
What makes glass good for windows? [3]
- Transparent
- Strong
- Good thermal insulator
What is a composite material?
A material consisting of two or more materials with different properties, which have been combined to produce a material with more desirable properties
What are the 2 components of a composite material?
- The reinforcement
- The matrix
What does fibreglass (composite material) consist of? [2]
Fibres of glass [1] embedded in a matrix made of plastic [1]
Why is fibreglass good for things like skis, boats and surfboards?
It has a low density but is very strong
What does carbon fibre (composite material) consist of? [2]
Carbon fibres [1] embedded in a matrix made of plastic [1]
Why is carbon fibre good for things like sports cars?
Light but very strong
What does concrete (composite material) consist of? [2]
Aggregate (sand and gravel) [1] embedded in cement [1]
Why is concrete good for building?
Very strong
What does wood (composite material) consist of? [2]
Cellulose fibres [1] embedded in an organic polymer matrix [1]
What 2 things influence the properties of a polymer?
- What monomers they’re made from
- Conditions under which they are made
THINK: temp + pressure
How is low density poly(ethene) made?
Made from ethene at a moderate temperature under a high pressure
Is low density poly(ethene) flexible or rigid?
Flexible
What is low density poly(ethene) used in?
Bags and bottles
How is high density poly(ethene) made?
Made from ethene at a lower temperature and with a catalyst
Is high density poly(ethene) flexible or rigid?
Rigid
What is high density poly(ethene) used in?
Water tanks and drainpipes
Describe the structure of thermosoftening polymers
Made from lots of polymer chains held together by weak intermolecular forces
Why can thermosoftening polymers be melted and moulded?
The weak intermolecular forces break easily when melted
Describe the structure of thermosetting polymers
Made from lots of polymer chains held together by strong covalent bonds
Why are thermosetting polymers hard, strong and rigid?
The strong covalent bonds require a lot of energy to be broken
Define ‘corrosion’
Where metals react with substances in their environment and are gradually destroyed
What is is called when iron corrodes?
Rusting
What conditions does iron need to rust? [2]
- Oxygen
- Water
What is the equation for the rusting of iron?
iron + oxygen + water —> hydrated iron(III) oxide
Compare the corrosion of iron and aluminium [2]
- When iron rusts, the rust flakes off to leave more iron available to rust again. This means that eventually all of the iron in an object corrodes away
- When aluminium corrodes it forms aluminium oxide which doesn’t flake off. In fact, it creates a protective layer which prevents any more aluminium from corroding
What are the 2 main methods to prevent objects from rusting?
- Barrier methods
- Sacrificial method
What are the 3 barrier methods to prevent rusting?
- Painting
- Electroplating
- Oiling/greasing
How does a sacrificial method prevent an object from rusting?
It involves placing a more reactive metal with the iron. Water and oxygen then react with the sacrificial metal instead of with the iron
Describe how galvanising prevents iron from rusting [2]
- Iron is sprayed with zinc which acts as a protective layer
- However, if the zinc is scratched, the zinc will act as a sacrificial method
Define ‘sustainable development’
Development that takes account of the needs of present society while not damaging the lives of future generations
What are the 4 stages of a Life Cycle Assessment?
- Extracting the raw materials
- Manufacturing and packaging
- Use of the product
- Disposal
Problems with LCAs [2]
- Effects of pollutants is hard to quantify
- Selective LCAs can be written to promote a companies’ products
Define ‘potable’ water
Water that is safe for humans to drink
Why is potable water not considered ‘pure’?
Pure water only contains H₂O molecules whereas potable water can contain lots of other dissolved substances
What are the 3 regulations that potable water has to meet?
- Levels of dissolved salts aren’t too high
- pH is between 6.5 - 8.5
- Aren’t any bacteria or microbes present
What are the 2 sources of fresh water in the UK?
- Surface water
- Groundwater
Describe the process of making water potable [3]
- Filter the water through wire mesh to get rid of any large particles e.g. twigs
- Filter it through gravel and sand beds to get rid of any smaller particles
- Sterilise the water to get rid of any harmful bacteria or microbes
What are the 3 ways of sterilising water?
- Bubbling it through chlorine gas
- Ozone
- Ultraviolet light
In hot countries, what is the main source of water?
Sea water
What are the 2 methods of desalination?
- Distillation
- Reverse osmosis
What are the problems with distillation and reverse osmosis?
Need lots of energy so are very expensive
What are the 3 sources of waste water?
- Household
- Agricultural
- Industrial
Describe the process of treating waste water (sewage) [6]
- The sewage is screened to remove any large bits of material
- The sewage is then left to stand in a settlement tank to undergo sedimentation
- The heavier solid sinks to the bottom to produce sludge and the lighter effluent floats at the top
- The sludge and effluent are separated
- The effluent is treated by biological aerobic digestion to break down organic matter and is then released back into the environment
- The sludge is broken down by bacteria in anaerobic digestion. This produces methane gas which is then used for fuel and the remaining digested waste is used for fertiliser
How is waste water containing toxic substances treated? [2]
- Adding chemicals
- UV radiation
What is the Haber process used to produce?
Ammonia
What 2 reactants are needed to produce ammonia?
Nitrogen and hydrogen
What is the production of ammonia used for?
Fertilisers
Where is the nitrogen involved in Haber process obtained from?
The air (78% nitrogen)
Where is the hydrogen involved in the Haber process obtained from?
Reacting methane with steam to form hydrogen and carbon dioxide
What are the conditions of the Haber process? [3]
- High temperature (450°C)
- High pressure (200 atm)
- Iron catalyst
What are the industrial conditions used in the Haber process and why? [3]
- A temperature of 450°C is used because this is high enough to ensure a fast rate of reaction without decreasing the yield of ammonia by too much
- A pressure of 200 atm is used in order to maximise the rate and the yield of the reaction. Higher pressure would be too expensive
- An iron catalyst is used to speed up the rate of reaction
What is a fertiliser?
A substance that is applied to soil, in order to supply plants with nutrients
What are the 3 elements in NPK fertilisers?
- Nitrogen
- Phosphorus
- Potassium
Why is nitrogen important for plants?
Plants require it to make amino acids and hence proteins, which are essential for growth
What is the main source of nitrogen in fertilisers?
Ammonia
How can ammonia be used to make nitric acid?
It can be reacted with oxygen and water
How can ammonia be used to make ammonium salts?
It can be reacted with acids (including nitric acid)
How can phospate used in fertiliser be obtained?
Can be mined from the ground as phosphate rock
What is the problem with phospate salts directly from rocks?
They are insoluble so cannot be used directly as fertilisers
What has to be reacted with phospate rocks to produce soluble salts?
Acids
What salt is produced when phosphate rock is treated with nitric acid?
Calcium nitrate
What salt is produced when phosphate rock is treated with sulfuric acid? [2]
Calcium sulfate and calcium phosphate
What salt is produced when phosphate rock is treated with phosphoric acid?
Calcium phosphate
What are the 2 sources of potassium in NPK fertilisers?
- Potassium chloride
- Potassium sulfate
Pure gold is said to have how many carats?
24
What is bronze made from?
Copper and tin
What is brass made from?
Copper and zinc
What is bronze used to make?
Medals
What is brass used to make?
Water taps
What are aluminium alloys used to make?
Aircraft
