(Topic 10) Using Resources (CGP Book) Flashcards
What are ceramics?
Non-metal solids with high melting points
How are ceramics made using clay?
Clay is a soft material when dug up out of the ground
So can be moulded into different shapes
When fired at high temperatures, it hardens to form a clay ceramic
How can Glass be used to make ceramics?
Glass is generally transparent, can be moulded when hot and can be brittle when thin
Most glass made is soda lime glass
What is soda lime glass?
Made by heating a mixture of limestone, sand, and sodium carbonate until it melts
It is then left to cool
What is borosilicate glass?
Higher melting point than soda lime glass
Made using a mixture of sand and boron trioxide
What are composites?
One material embedded in another
Fibres or fragments of a material are surrounded by a matrix acting as a binder
What are examples of composites?
Fibreglass
Carbon fibre
Concrete
Wood
What is fibreglass?
Consists of fibres of glass embedded in a matrix made of polymer
Has a low density, but is very strong
What is carbon fibre?
Have a polymer matrix
Reinforcement is either made from long chains of carbon atoms bonded together from carbon nano tubes
These composites are very strong and light
What is concrete?
Made from aggregate, which is a mixture of sand and gravel, embedded in cement
Very strong
What is wood?
A natural composite of cellulose fibres held together by an organic polymer matrix
What is low density polythene made from?
Eating at a moderate temperature under a high-pressure
It is flexible
What is high density polythene made from?
Ethan, but at a lower temperature and pressure with a catalyst
More rigid
What are thermo softening polymers?
Contain individual poly machines and twined together with weak forces between the chains
Can be melted and remoulded
What are thermosetting polymers?
Contain monomers that can form cross-links between the polymer chains, holding the chains together in a solid structure
Don’t soften when heated
Strong, hard and rigid
Properties of polymers
Insulators
Flexible
Easily moulded
Properties of metals?
Malleable
Good conductors
Ductile
Shiny
Stiff
Properties of ceramics?
Insulators
Brittle
Stiff
What are commonly used alloys?
Bronze - copper + tin
Brass - copper + zinc
Gold alloys
Aluminium alloys
Properties and Uses of bronze?
Medals, decorative ornaments, and statues
Harder than copper
Properties and uses of brass?
More malleable than bronze
Water taps and door fittings
Properties and uses of gold alloys?
Jewellery
Uses and properties of aluminium alloys?
Make aircraft
Low density
What is corrosion?
Where metals react with substances in their environment and are gradually destroyed
Only happens on the surface of a material
What is required for corrosion?
Oxygen and water
What is rusting?
When iron comes into contact with oxygen and water leading to corrosion
Why is aluminium protected from further corrosion?
When the aluminium oxide forms, it doesn’t flake away leaving a protective layer
What are the main ways to prevent the rusting?
Painting/coating with plastic
Electroplating
oiling/greasing
Sacrificial
Galvanising
What is electroplating?
Using electrolysis to reduce metal ions onto an iron electrode
Can be used to quote the iron with a different layer of a different metal that won’t corrode away
Where do natural resources come from from
The Earth, the sea, and the air
What is a renewable resource?
Resource that reforms at a similar rate to, or faster than we use them
What are finite resources?
Resources that are not formed quickly enough to be considered replaceable
What is bioleaching?
Bacteria used to convert the metal compounds in the ore into soluble metal compounds
This separate out the metal from the ore in the process
The solution produced by this process contains the metal ions which can be extracted
What is phytomining?
Involves growing plants in soil that contains metal
The plants can’t use or get rid of the metal, so it gradually builds up in the leaves
The plants can then be harvested, dried, and burned in a furnace
The ash contains soluble metal compounds from which metal can be extracted by electrolysis or displacement
How are metals recycled?
By melting them and then casting them into the shape of a new product
What is the job of a life-cycle assessment?
Looks at every stage of a product life to assess the impact it would have on the environment
What are the four stages of the life-cycle assessment?
Getting the raw materials
Manufacturing and packaging
Using the product
Product disposal
What is potable water?
Water that is safe to drink
When is water deemed potable?
When the levels of dissolved salts aren’t too high
That it has a pH between 6.5 and 8.5
No bacteria or other microbes
How can water be cleaned to drink?
Filtration – a wire mesh screens out large twigs, then gravel and sand beds filter out any other solid bits
Sterilisation – the water is sterilised to kill any harmful bacteria on microbes
Steps to the water treatment practical?
Test PH of water using PH meter
Test water for presence of sodium chloride
Test for sodium ions by doing flame test
Pour water into distillation apparatus , and heat the flask
Steam will condense back to liquid of water in the condenser and can be collected
Distilled water for sodium chloride to check that it has been removed and retest the PH
How can sea water be treated?
Salty water is passed through a membrane that only allows water molecules to pass through
Ions and larger molecules are trapped by the membrane
Steps of the sewage treatment?
Sewage is screened
Allowed to stand in a settlement tank and undergo sedimentation
The effluent in the settlement tank is removed and treated by biological aerobic digestion
Air is pumped through the water to encourage air aerobic bacteria to breakdown any organic matter
Sludge from the bottom of the settlement tank is removed and transferred into large tanks to be broken down in a process called anaerobic digestion
This releases meeting us which can be used as an energy source and remaining digested waste can be used as a fertiliser
What does the haber process produce?
Ammonia
How is ammonia made?
Nitrogen and hydrogen
Steps to the Heber process?
Nitrogen obtained from air
Hydrogen from reacting methane with steam
Gases passed over an iron catalyst
a high temperature and a high-pressure are used
Because the reaction is reversible, Some ammonia produced convert back into hydrogen and nitrogen again. It eventually reaches a dynamic equilibrium.
Ammonia is formed as a gas but cools in the condenser and is removed
Unused reactants are recycled
Job of NPK fertilisers?
Provide plants with the essential elements for growth
This increases plant yield
What does NPK stand for?
Nitrogen, phosphorus, and potassium
These are essential for plant growth
What is produced when phosphate rock is reacted with different types of acids?
Reaction with nitric acid produces phosphoric acid and calcium nitrate
Reaction with sulphuric acid produces calcium sulphate and calcium phosphate
Reaction with phosphoric acid only produces calcium phosphate
