USING RESOURCES Flashcards
What are ceramics?
Non-metal solids with high boiling/melting points
Not made from carbon-based compounds
(Can be made from clay)
How can clay be made as a ceramic?
When dug up it is soft so can be moulded
Fired at high temps to harden to form a clay ceramic
(Pottery and bricks)
How can glass be made as a ceramic?
Can be moulded when hot
Brittle when thin
How is soda lime glass made?
Made from heating limestone, sand and sodium carbonate until it melts then cools
What is borosilicate glass?
Has higher melting point than soda-lime glass
Made by mixing sand and boron trioxide
What are composites?
Made of one material embedded in another
What is an example of a composite?
Fibres or fragments (reinforcement) of material surrounded by a matrix (acts as a binder)
What is fibreglass?
Fibres of glass embedded in a matrix made of polymer (plastic)
What can fibreglass be used for?
Skis
Boats
Surfboards
What is carbon fibre?
Polymer matrix
Reinforcement of either chains of carbon atoms bonded together or carbon nanotubes
What does a composite contain?
Reinforcement (fibre/fragment of material)
Matrix (surrounds the reinforcement)
What affect the properties of a polymer?
How it’s made and what it’s made from
How is low density poly(ethene) made?
Moderate temp and high pressure with a catalyst
(Flexible for bags and bottles)
How is high density poly(ethene) made?
Lower temperature and pressure with a different catalyst
(More rigid so for water tanks etc)
What influences the properties of poly(ethene)?
The catalyst
Reaction conditions (temp and pressure)
What is poly(ethene) made from?
Ethene
What determine the type of bonds that form between polymer chains?
The monomers that a polymer is made from
What determines the properties of a polymer (bonds)?
The monomers which create different weak bonds
What do thermosoftening polymers contain?
Individual polymer chains entwined together with weak forces (melt and remould)
What do thermosetting polymers contain?
Monomers that form cross links between polymer chains so solid structure (strong, hard, rigid)
What are the properties of ceramics?
Insulators of heat and electricity
Brittle
Stiff
What are the properties of composites?
Depend on the matrix/binder and reinforcement
What are the properties of metals?
Good conductors of heat and electricity
Ductile (drawn into wires)
Shiny
Stiff
What are the properties of polymers?
Insulators of heat and electricity
Flexible
Can be moulded easily
What is bronze made out of?
Tin and copper
What is brass made out of?
Copper and zinc
What metals can be used to harden gold (alloy)?
Zinc
Copper
Silver
How is aluminium made stronger?
Alloyed with small amounts of other metals to make it stronger
What is corrosion?
Where metals react with substances in their environment and are gradually destroyed
What is the word equation for when iron rusts?
Iron + oxygen + water -> hydrated iron (III) oxide
What is needed for iron to rust?
Oxygen and water
Where does corrosion occur?
On the surface of a material where it is exposed to air
Why does all of iron corrode even when not on surface?
Rust is soft and crumbly and flakes off which leaves more iron to rust again
What happens to aluminium when it’s corroded?
The aluminium oxide doesn’t flake away so it isn’t completely destroyed
How can you prevent rusting?
Painting/coating with plastic
Electroplating
Oiling/greasing
Sacrificial method
What is electroplating?
Uses electrolysis to reduce metal ions onto an iron electrode (coats iron with different metal that won’t corrode away)
What is the sacrificial method?
Placing a more reactive metal with iron so the water and oxygen then react with the sacrificial metal instead
What are natural resources?
They form without human input
What are renewable resources?
Resources that reform at a similar rate to/faster than we use them
What are finite resources?
Resources that aren’t formed quickly enough to be considered replaceable
What are examples of finite resources?
Fossil fuels
Nuclear fuels (uranium and plutonium)
Minerals and metals found in ores
What is sustainable development?
An approach to development that takes account of the needs of present society while not damaging the lives of future generations
What is bioleaching?
Bacteria is used to convert copper compounds in the ore into soluble copper compounds (separates the copper from ore)
Leachate (solution) contains copper ions which can be extracted by electrolysis or displacement
What is phyotiming?
Growing plants in soil that contains copper so copper gradually builds up in leaves
Plant harvested, dried then burned
Ash contains copper compounds which can be extracted using electrolysis
Why is recycling metals good?
Uses less energy than is needed to mine new metals
Conserves the finite amount of each metal
Cuts down on waste getting sent to landfill
How can metals be recycled?
Melting then casting them into new desired shape
How is glass recycled if it cannot be reused?
Separated by colour and chemical composition
Crushed then melted to be reshaped
What is a life cycle assessment?
It looks at every stage of a products life to assess the impact it would have on the environment
What are the stages a LCA looks at?
Getting the raw materials
Manufacturing and packaging
Using the product
Product disposal
What are the limitations of LCAs?
Can be biased
Can be selective as support claims of companies so they can advertise positively
Hard to give a numerical value to the effects of some pollutants
What is potable water?
Water that has been treated or is natural safe so you can drink it
What is fresh water?
Water that doesn’t have much dissolved in it
How is rain collected?
Collect as surface water or groundwater
How is fresh water made safe?
Filtration (wire mesh)
Sterilisation (kills any harmful bacteria of microbes)
How can sea water be made drinkable (desalinate)?
Distillation
Reverse osmosis
How does reverse osmosis work?
Salty water is passed through a membrane that only allows water molecules to pass through it
Ions and larger molecules are trapped by the membrane so are separated out
Why does sewage water have to be treated?
Has to remove any organic matter and harmful microbes before it can be released into any freshwater sources otherwise it can pollute them and cuase health risks
What are the stages of sewage treatment?
Screening (large sediment)
Sedimentation (sludge produced at bottom and effluent at top)
Aerobic digestion (breaks down organic matter/microbes in effluent)
Anaerobic digestion (sludge broken down by bacteria)
What happens during sedimentation (sewage treatment)?
Heavier suspended solids sink to bottom of settlement tank and become sludge
Lighter effluent floats on top
What happens during aerobic digestion (sewage treatment)?
Air is pumped through the water to encourage aerobic bacteria to break down any organic matter
What happens during anaerobic digestion (sewage treatment)?
Sludge gets broken down by bacteria and produces methane gas which can be used for energy and the rest for fertilisers
What is the Haber process?
When ammonia is made from hydrogen and nitrogen
What is the equation for the Haber process?
N2 + 3H2 –> 2NH3
How do you obtain hydrogen?
Reacting methane with steam to form hydrogen and carbon dioxide
What do you need to create ammonia?
Reaction vessel
Iron catalyst
High temp
High pressure
What type of reaction creates ammonia?
Reversible reaction
What compromises are made during the Haber process?
Increasing temp means more reactants not products but decreasing temp means too slow
Increasing pressure increases products but too high a pressure is dangerous and expensive
Why are formulated fertilisers better than manure?
Smell less
More widely available
Easier to use
Just enough nutrients for crops to grow
What are the three main essential elements in fertilisers?
Nitrogen
Phosphorus
Potassium
How do fertilisers increase crop yield?
By replacing missing elements/nutrients or provide more in the soil so crops can grow faster and bigger
What are NPK fertilisers?
A formulation containing salts of nitrogen, phosphorus and potassium in the right percentages
How can nitric aid be made?
By reacting ammonia with oxygen and water
How can ammonium salts be made?
By reacting ammonia with acids (e.g. nitric acids)
What do ammonia and nitric acid react to produce?
Ammonia nitrate which is a good fertiliser
How is ammonia nitrate produced in a lab?
Titration then crystallisation
What happens when you react a phosphate rock and nictric acid?
Produces phosphoric acid and calcium nitrate
What happens when you react a phosphate rock and sulfuric acid?
Produces calcium sulfate and calcium phosphate
What happens when you react a phosphate rock and phosphoric acid?
Produces calcium phosphate
How do you obtain potassium?
Mine potassium chloride and potassium sulphate
How do you obtain soluble phosphates?
Mine phosphate rock then react it with different acids
