Topic 10 - Using resources Flashcards
What does NPK stand for in NPK fertilisers?
N - Nitrogen
P - Phosphorous
K - Potassium
In what form can plants absorb nutrients?
Plants can only absorb nutrients as ions that are water soluble.
What is the formula for the reaction to form ammonium nitrate?
NH3 + HNO3 –> NH4NO3
Ammonia + Nitric acid –> Ammonium nitrate
What substance is ammonium nitrate?
A salt
How is ammonium nitrate made in the lab?
- ammonia solution in low concentration is titrated with nitric acid and then undergoes crystalisation. It is a low concentration as it releases less heat.
How is ammonium nitrate made in industry?
Ammonia gas is directly added to the reaction vates containing high concentration nitric acid.
How is potassium for NPK fertilisers obtained?
It is mined from sylvite deposits and potassium sulfate
How is phosphorous obtained for NPK fertilisers?
Rock is mined which is then reacted with acids to form salts.
How do different rock reactions produce phosphorous?
- with nitric acitd produces phosphoric acid and calcium nitrate
- with sulfuric acid produces calcium sulfate and calcium phosphate
- reaction with phosphoric acid produces produuces calcium phosphate(this one is known as triple superphosphate)
What are the advantages of NPK fertilisers?
Contains the right mix of nutrients.
What is the equation for the Haber process?
3H2 + N2 <–> 2NH3
Is the forward of reverse reaction of the Haber process exothermic?
Forward is exothermic, backwards is endothermic
What are the best conditions for the Haber process?
- Lower temperature(450°C)
- High pressure - 200ATM
- Catalyst - iron
- More reactant
What does the N2 and 3H2 come from in the Haber process?
N2 from the atmosphere and 3H2 from reacting methane with steam
What is the equation for obtaining 3H2 from methane and steam?
CH4 + 2H2O —> 3H2 + CO2
How is ammonia removed in the Haber process?
The ammonia is removed by condensing it into a liquid
What is the reason for the temperature in the Haber process?
450°C is used as it is a compromise between rate and yield - a higher temp increases the rate but reduces the yield
What is the reason for the high pressure in the Haber process?
200Atm is used as it favours the forward reaction, it is expensive to maintain however.
Why is a catalyst used in the Haber process?
Iron is used as a catalyst to speed up the reaction, save energy and increase yield.
How is waste water treated?
- Screening - removes any large material
- Sedimentation - separates out a liquid effluent at the top, and a sewage sludge at the bottom.
- The effluent undergoes aerobic digestion to be released into the environment
- The sludge undergoes anaerobic respiration
What can we turn sludge into and how?
- Fertiliser by making it undergo anaerobic digestion
- Methane to be burned after anaerobic respiration
How can water be made potable outside the UK?
- Reverse osmosis
2.Desalination
What is reverse osmosis?
- Forcing water through a PPM
2.The PPM blocks all the ions and larger molecules , separating it from water.
3.Freshwater is not needed for this
How does desalination work?
1.Water sample heated
2.water evaporates at it’s boiling point
3.Cools and condenses as it passes through a condenser
4. Impurities are left in the flask
5. Pure water will be left in the beaker
6. Test water with flame to check purity
What are disadvantages of reverse osmosis and desalination?
both require lots of energy making it very expensive
What is potable water?
Water that is drinkable, has a pH of 6.5-8.5 and is free from microves
How do we make freshwater potable in the UK?
- Water passes through a large mesh which removes large insoluble solids
2.sand and gravel filter removes smaller substances
3.sterilisation kills microbes using UV light or chlorine
What are natural resources?
Resources formed without human imput
What are renewable resources?
Resources what can be made at the same rate as it is being used.
What are finite resources?
Resources which are being used at a faster rate than being replaced.
What is sustainable development?
Taking into account the present needs of society while not damaging the lives of future generations.
What damage does extracting materials cause?
1.habitat destruction
2. Pollution caused by machinery
3. Greenhouse emissions from transport
4. Reduction, distillation, electrolysis produce waste
5.burbing fossil fuels release greenhouse gases
What damages can manufacturing and packaging cause?
- Requires lots of energy from fossil fuels, which release greenhouse gases
- Pollution like CO and hydrogen chloride is harmful
- Lots of waste product
What are the damages of using a product?
- Can directly cause damage, like fertilisers when they leak into rivers or lakes
- Petrol or other fuels release greenhouse gases.
- Plastic doesn’t decompose
How can we reduce the impact of using a product?
- Use it for longer
- Recycle or reuse it
What damage can product disposal cause?
- Transport of waste releases fossil fuels
- Landfill is space inefficient
- Plastic takes thousands of years to decompose
- Waste causes problems in water
- Incineration releases air pollution
What are some problems with the life cycle assessment?
- Difficult to put a value on some types it pollution
- Not fully objective
- Can be biased to support certain companies
What are the different alloys of iron?
- High carbon steel
- Low carbon steel
- Stainless steel
What is added to iron to make it stainless steel?
Chromium or nickel
What are the properties and uses of low carbon steel?
- Easy to shape
- Car bodies
What are the properties and uses of high carbon steel?
- Very strong, brittle, inflexible
- Blades for cutting tools, bridges
What are the properties and uses of stainless steel!
- Corrosion resistant and hard
- Cutlery, containers
What are ceramics?
non-metal solids with high melting points that aren’t made from carbon based compounds - sometimes made of clay
How do you make clay ceramic from clay?
mould it how you like and then fire it at high temperatures to make it harden into clay ceramic
What is clay good for?
Moulding to make pottery and bricks
What are examples of ceramics
- glass
- porcelain
- brick
How is glass usually made?
- most glass is soda-lime glass
- this is made by heating a mixture of limestone, sand and sodium carbonate until it melts - as it cools it becomes glass
How is boroscilicate glass different to soda-lime glass?
- It has a higher melting point
- It’s made using a mixture of sand and boron trioxide instead
What are composites?
substances made of one material embedded in another
What are the 4 different composites you need to know?
- fibreglass
- carbon fibre
- concrete
- wood
What does fibreglass consist of?
fibres of glass embedded in a matrix of polymer(plastic)
what are the properties of fibreglass?
- low density - like plastic
- high strength - like glass
What is fibreglass used in?
1.sufboards
2.skis
3.boats
what does carbon fibre consist of?
comprised of a polymer matrix, and long chains of carbon atoms or carbon nanotubes as the reinforcement.
What are the properties of carbon fibre?
- strong
- light
What is concrete comprised of?
aggregate embedded in cement
What is aggregate?
a mixture of sand and gravel
What is wood comprised of ?
cellulose fibres held together by an organic polymer matrix
what is the general structure of a composite?
Fribres or fragments of a material are surrounded by a matrix acting as a binder
What are the 2 things which can influence the properties of a polymer?
- how it’s made
- what it’s made from
What are the properties of low density polyethene and how is it made?
- it is flexible
- it is made from ethene at a moderate temperature under high pressure
What are the properties of high density polyethene, and how is it made?
- more rigid than low density polyethene
- Made from ethene but at a lower temperature and pressure, and uses a catalyst
What is the structure of a thermosoftening polymer, and its properties
- contain inducidual polymer chains entwined together with weak forces between the chains.
- when heated, it melts and can be remoulded
What is the structure of a thermosetting polymer and its properties
- contains monomers that can form cross links between the polymer chain, holding the chains together in a solid structure.
- Don’t soften when heated, instead they are strong, hard and rigid
What are the properties of ceramics?
- insulators
- brittle
- stiff
what are the properties of polymers?
1.insulators
2.flexible
3.easily moulded
What are the properties of metals?
- malleable
- good conductors
- ductile
- shiny
- stiff
What is bronze made of, and what are it’s properties
- copper+tin
- harder than copper
What is brass made of and what are its properties?
- copper + zince
- More malleable than bronze
What/why are aluminium alloys used for?
- used in aircraft manufacturing, as it is low density
- aluminium has low density, but is too soft, so alloys are used
What is corrosion?
Where metals react with substances in their environment and are gradually destroyed
What is the formula for iron rusting?
iron + oxygen + water —> hydrated iron(III) oxide
what is needed for iron to rust?
water and oxygen
How does aluminium rust protect aluminium?
- Aluminium rusts and forms aluminium oxide on the surface
- this doesn’t flake off and creates a protective barrier
How can we test what is needed for iron to rust?
- place iron nail in boiled water, with a layer of oil on top - this won’t rust
- Place iron nail in boiling tube with calcium chloride to take oxygen out of air - it won’t rust
- PLace iron nail in air and water - it will rust
What are the 2 ways we can prevent rusting?
- a physical barrier
- sacrificial method
What are 4 materials which can act as a physical barrier?
- paint
- coating with plastic
- electroplating
- oiling/greasing
What is electroplating?
uses electrolysis to reduce metal ions onto an iron electrode - this covers the iron in another layer of metal that won’t be corroded
What is the sacrificial method?
Placing a more reactive metal such as zinc or magnesium with the iron, so the water and oxygen react with it instead
what is galvanising?
coating iron with zinc to act as a barrier but also as a sacrificial metal
How can we improve copper extraction sustainability?
extracting it from low-grade ores, using bioleachin and phytomining
What is phytomining?
1.Growing plants in soil that contains copper.
2. The plants can’t use the copper so it builds up in the leaves.
3. These plants are then harvested, dried and burned in a furnace.
4. The ash contains soluble copper compounds from which copper can be extracted using electrolysis or displacement using scrap iron
What is bioleaching?
1.bacteria are used to convert copper compounds in the ore into soluble copper compounds, separating out the copper in the process.
2.The leachate contains copper ions which can be extracted by electrolysis or displacement.
What is a leachate?
the solution produced by bioleaching
What is a life a life-cycle assessment?
An assessment which looks at every stage of a product’s life and checks the impact it would have on the environment
What are alloys?
Substances made by adding another element to a metal. This disrupts the regular layers, making the alloy harder.
What are gold alloys made of, and what are the properties?
1.Metals like zinc, copper and silver are used to harden the gold.
2.Gold is measured in carats, 24 is pure, 0 is, idk tbh.
How do you make nitric acid, for making ammonium nitrate
NH3 + 2O2 —> HNO3 + H2O
ammonia + oxygen —-> Nitric acid + water
