Using Resources Flashcards
What are ceramics?
Non- metal solids with high melting points that aren’t
made from carbon-based compounds
How is clay used?
It’s soft so can be moulded then fired until hardened by losing water making it Extremely brittle
How is glass made (soda-lime glass)?
Mixing limestone, sand and sodium Carbonate until it melts, when cooled it is glass
What are the properties of borosilicate glass and how is it made?
It has a higher melting point than soda-lime glass
Made the same way as soda-lime glass using sand and boron trioxide
What are composites
2+ materials embedded in each-other
What is fibre glass?
Glass fibres embedded in a matrix of polymer
Low density
Very strong
Used for boats and skis
What is carbon fibre?
Polymer matrix
Long chains of carbon atoms bonded together or carbon nanotubes
Very strong and light
What is concrete?
Sand and gravel embedded in cement
Very strong
Building materials
What’s Wood?
Natural composite of cellulose fibres held together by organic polymer matrix
How is low density poly(ethene) created? Properties and uses?
Moderate temperature, high pressure, flexible, used for bags and bottles
How is high density poly(ethene) made? Properties? Uses?
Lower temperature and pressure, catalyst
Rigid used for water tanks
What are thermosoftening polymers structure?
Individual polymer chains entwined together, weak forces between chains
Can melt and remould
What’s the structure of Thermosetting polymers?
Monomers that form cross links between polymer chains , holding them in solid structure
Don’t soften when heated they char when at high enough temp
Strong hard and rigid
What are polymers?
Insulators of heat and electricity that are flexible and easily moulded
What are glass and clay ceramics good for?
Porcelain and brick are insulators of heat and electricity, they are brittle and stiff
What do the properties of a composite depend on?
The matrix/binder and the reinforcement used to make them
What are metals properties?
Malleable, good conductors of heat, electricity, they are ductile, shiny and stiff
How are alloys made?
Adding another element to the metal to disrupt the structure making them harder than metals
How are alloys of iron (steel) made?
adding small amounts of carbon and sometimes other metals to the ipn
What is needed for rust to occur?
Oxygen and water
Why does all of the iron corrode away after time instead of just the part with rust on it?
The rust begins to flake off leaving more areas exposed to corrosions and to continue to flake off
Why does aluminium corrode but not completely?
Aluminium oxide forms during corrosion doesn’t flake away and forms a protective layer
What are methods used to prevent rusting?
BARRIER
(painting,polymer coating, electroplating, oiling/greasing)
SACRIFICIAL METHOD
place more reactive metal e.g zinc or magnesium so water and oxygen react with that
GALVANISATION
sprayed with zinc coating
What do you have to balance with extracting finite resources?
Social, economic and environmental effects
What is bio leaching?
Bacteria convert copper compounds into soluble copper compounds
The leachate contains copper ions that can be extracted by electrolysis or displacement
What’s phytomining?
Growing plants in soil containing copper
Plants can get rid of it so builds up in leaves
Plants harvested, dried and burned
Ash contains soluble copper
How is glass recycled?
Some glass bottles can just be reused
Glass separations by colour and chemical composition
Glass crushed and melted
Reshaped
What’s a life cycle assessment?
Looking at every stage of the products life and assess the impact on the environment
What’s the 1st step of a life cycle assessment?
Getting the raw material
Extraction can damage environment
Need to be processed to extract desired materials , requiring large amounts of energy
What’s the 2nd step of a life cycle assessment?
Manufacturing uses lots of energy and pollution
Need to dispose of waste products
What’s the 3rd step of a life cycle assessment?
Using the product
Fertilisers can leach and urning fuels releasing green house gases
How long it’s used for
What’s the 4th step of a life cycle assessment?
Disposal in landfill
Energy for transportation to landfill
Can be burnt causing air pollution
What is a problem with the life cycle assessment?
Effects of some pollutants is hard to give numerical value
Can be bias
Selective LCA can be written to support claims of a company
What is potable water?
Water that has been treated and is safe for humans to drink
What is filtration?
Wire mesh screens out large twigs, gravel and sand beds filter out solid bits
What is sterilisation?
Water is sterilised to kill harmful bacteria and microbes
Bubbling chlorine gas through water or using ultraviolet light
What is done when there isn’t enough surface or ground water?
They use sea water which they desalinate
How can you test and distil water in the lab?
find pH of water (if too high you can neutralise)
test for presence of sodium chloride
(flame test on small sample) will turn yellow
for chloride add dilute nitric acid and silver nitrate to form a white precipitate
how do you distill water?
pour salty water into distillation apparatus
heat flask from below
water boils and steam forms leaving dissolved salts in flask
steam will condense back into liquid in the condenser and can be collected
retest the distilled water for sodium chloride to check
what is reverse osmosis?
sea water passed through a membrane that only allows water molecules to pass through, larger ions are trapped and seperated by membrane
Why are distillation and reverse osmosis not that good?
require lots of energy, very expensive, not practical for producing large quantities
how does sewage treatment happen?
1.) sewage is screened (removing large objects)
2.) stands in settlement tank and undergoes sedimentation (sludge sinks to bottom)
3.) effuent in settlement tank is removed and treated by biological areobic digestion
4.) sludge from bottom of settlement tank removed and transferred to large tanks to be broken down by anaerobic digestion
5.) sludge broken down releasing methane, methane can be used as energy
6.)waste water containing toxic substances can have chemicals added, uv or membranes
whats the haber process equation?
nitrogen + hydrogen – ammonia + heat
where is nitrogen obtained?
the air
where does the hydrogen for the haber process come from?
reacting methane and steam
what happens during the haber process?
nitrogen and hydrogen passed over an iron catalyst at 450 degrees c and a high pressure 200atmospheres
ammonia formed as a gas, cools in condenser and liquefies
unused products are recycled
what are the 3 main essential elements in fertilisers?
nitrogen, phosphorus and potassium
what are NPK fertilisers?
formulations containing salts of nitrogen, phosphorus and potassium in the right percentages
what does ammonia + oxygen and water create?
nitric acid
what does ammonia + acids create?
ammonium salts
what does ammonia + nitric acid create?
ammonium nitrate
how is ammonia converted in the industry?
giant vats, high concentrations, very exothermic reactions, heat released used to evaporate water from mixture, makes concentrated ammonia product
how is ammonia converted in the lab?
much smaller scale by titration and crystallisation
reactants = lower concentration, less heat produced
crystallise mixture after titration to give pure ammonium nitrate crystals
crystallisation isnt used in industry as its very slow
