C10- Using Resources Flashcards
How is soda-lime glass made
By heating a mixture of limestone, sand and sodium carbonate (soda) until it melts. When the mixture cools it comes out as glass
Give three examples of composite materials
- Fiberglas
- Carbon fibre
- Concrete
- Wood
Describe the difference in the properties of low density poly(ethene) and high density poly(ethene)
low-density polyethylene (LDPE) has a lower density, strength, and temperature resistance. Meanwhile, high-density polyethylene (HDPE) is characterised by higher specific strength and heat resistance.
Name two elements that can be added to iron to make stainless steal
Chromium and nickel
What two metals is bronze made of
Copper and tin
Give two uses of brass
Applications where low friction and corrosion resistance is required, such as locks, hinges, gears, bearings, ammunition casings, zippers, plumbing, hose couplings, valves, and electrical plugs and sockets.
What two substances does iron react with when its rust
Oxygen and water
Aluminium objects can corrode. Why is aluminium not completely destroyed by corrosion
Aluminium oxide that forms when aluminium corrodes
Suggest three ways of making barrier that can be used to protect an iron object from rusting
- Oiling
- Painting
- Greasing
Suggest one metal that can be used in the sacrificial method to prevent rusting
Magnesium and zinc
Give two examples of renewable resources
Wind energy
Solar energy
Suggest one way in which chemistry is improving sustainability
It provides chemicals, materials, and technologies that improve the safe and efficient use of energy and natural resources and is responsible for delivering them in a way that protects human and environmental health.
State two methods that an be use to extract copper from low grade ores
- Bioleaching
- Phytomining
Other than recycling, how can glass bottles be used in a sustainable way
- Can be reused without reshaping
What do life cycle assessments (LCA) do
Looks at every stage of a product’s life to assess the impact it would have on the environment
What is a potable water
Water that’s been treated or id naturally safe for humans to drink
Suggest a source of fresh water
Rain water
Describe how you could distil seawater in the lab
Through a processes that use membranes- like reverse osmosis. The salty water is passed through a membrane that only allows water molecules to pass through. Ions and larger molecules are trapped by the membrane so separated from the water
describe how Filtration works
A wire mesh screens out large twigs etc, and then gravel and sand beds filter out any other solid bits
Describe how Sterilisation works
The water is sterilised to kill any harmful bacteria or microbes. This can be done by bubbling chlorine gas through it or by using ozone or ultraviolet light
What other method could you use for making sea water potable
Desalination
Filtration
Sterilisation
Name three different sources if waste water
Domestic sewage
Industrial sewage
Storm sewage
Why is it important to treat waste water before releasing it into the environment
The major aim of wastewater treatment is to remove as much of the suspended solids as possible before the remaining water, called effluent, is discharged back to the environment. As solid material decays, it uses up oxygen, which is needed by the plants and animals living in the water.
What type of waste water could contain harmful chemicals
Organic matter
What two products can be obtained by the anaerobic digestion of sewage sludge
Biogas
residual digestate
What is the balanced symbol equation for the Haber process
N2(g) + 3H2(g) ⇌ 2NH3(g) (+heat)
From what source is the hydrogen used in the Haber process obtained
natural gas (mostly methane )
What happens to the unused hydrogen and nitrogen in the Haber process
The unreacted hydrogen and nitrogen gases are recycled by being fed back through pipes to pass through the hot iron catalyst beds again
What three elements are present in NPK fertilisers
Nitrogen, phosphorus and potassium
What substance can be reacted with each other to produce the following
a) Aluminium nitrate
b) phosphoric acid and calcium nitrate
c) Calcium phosphate only
a)nitric acid with aluminium hydroxide
b)Calcium nitrate is produced by applying nitric acid to limestone and then adding ammonia. Phosphoric acid is hydrogen and Phosphate
c ) Phosphoric acid and phosphate rock
Iron + oxygen water →
hydrogen iron (III) oxide
What is sustainable development?
Development that meets the needs of current generations without compromising
the ability of future generations to meet their own needs
In the UK, potable (safe to
drink) water is produced by…?
- choosing an appropriate source of fresh water
- passing the water through filter beds to remove any solids
- sterilising to kill microbes
What are the sterilising agents for potable
water?
Sterilising agents used for potable water include chlorine, ozone or ultraviolet light.
• Chlorine is a toxic gas so the amount added to water has to be carefully
monitored.
• Using ultraviolet light to kill microbes avoids adding chemicals to the water but is
more expensive
How is desalination carried out?
Desalination can be done by distillation or by processes that use membranes such
as reverse osmosis. These processes require large amounts of energy.
What is reverse osmosis?
Sea water is passed through a membrane that only allows through the water
molecules. It needs high pressure to push the water through the membrane. The
high pressure requires a lot of energy to produce
How is wastewater produced and how is it
treated?
• Urban lifestyles and industrial processes produce large amounts of waste water
that require treatment before being released into the environment.
• Sewage and agricultural waste water require removal of organic matter and
harmful microbes.
• Industrial waste water may require removal of organic matter and harmful
chemicals.
What are the processes involved in sewage
treatment?
Sewage treatment includes:
- screening and grit removal
- sedimentation to produce sewage sludge and effluent
- anaerobic digestion of sewage sludge
- aerobic biological treatment of effluent
What do new methods of mining avoid in terms
of disadvantages of traditional mining?
Avoids the disadvantages of traditional mining methods of digging, moving and
disposing of large amounts of rock
What is phytomining?
Phytomining uses plants to absorb metal compounds from the soil. The plants are
harvested and then burned to produce ash that contains the metal compounds
What is bioleaching?
Bioleaching uses bacteria to produce leachate solutions that contain metal
compounds.
What are the main advantages
and disadvantages of
phytomining and bioleaching?
These methods need less energy than traditional methods, and can work on low
concentration ores but are slow to carry out.
Describe the stages of LCAs
Life Cycle Assessments (LCAs) are carried out to assess the environmental
impact of products in each of these stages:
- extracting and processing raw materials
- manufacturing and packaging
- use and operation during its lifetime
- disposal at the end of its useful life, including transport and distribution at
each stage.
How do we reduce the use of resources?
The reduction in use, reuse and recycling of materials by end users reduces the
use of limited resources, energy consumption, waste and environmental impacts.
What are the advantages and disadvantages of
recycling?
Advantages of recycling: less acid rain (pollution) metal ore reserves last longer /
conserved energy for extraction saved less mining / quarrying less waste less
landfill creates local employment
Disadvantages of recycling ; collection problems transport problems/ cost of
transport difficult to separate metal from appliances/sort
What is corrosion and how is it prevented?
Corrosion is the destruction of materials by chemical reactions with substances in
the environment, e.g. rusting.
Corrosion can be prevented by applying a coating that acts as a barrier, such as
greasing, painting or electroplating. These methods stop the air or water coming
into contact with the metal
Describe the sacrificial protection
Some coatings are reactive and may contain corrosion inhibitors or a more
reactive metal.
If two metals are in contact the more reactive metal will corrode instead of the less
reactive one, e.g. zinc is used to galvanise iron and when scratched, provides
sacrificial protection because zinc is more reactive than iron.
Describe the compounds and the
uses of bronze, brass, gold and
silver and copper and zinc,
aluminium-magnesium and steels
Alloys:
Bronze - an alloy of copper and tin, used for making statues and decorative objects.
Brass - an alloy of copper and zinc used for producing water taps and door fittings.
Gold used as jewellery is usually an alloy with silver, copper and zinc (The proportion of gold in the alloy is
measured in carats, with pure gold being 24 carat, e.g. 18 carat gold is 75% gold.)
Aluminium-magnesium alloys are low density and used in aerospace manufacturing.
Steels - alloys of iron that contain specific amounts of carbon and other metals. High carbon steel is
strong but brittle. Low carbon steel is softer and more easily shaped. Steels containing chromium and
nickel (stainless steels) are hard and resistant to corrosion.
How are the properties of polymers determined?
The properties of polymers depend on what monomers they are made from and
the conditions under which they are made. For example, low density (LD) and high
density (HD) poly(ethene) are produced from ethene, using different catalysts and
reaction conditions.
Describe the structures of thermosoftening and
thermosetting polymers
Thermosetting polymers do not melt on heating. The polymer molecules are linked
to each other by strong cross-links. Thermosoftening polymers soften easily on
heating and can then be remoulded, keeping the new shape on cooling. The
polymer molecules are attracted to each other by weak intermolecular forces.
How is glass made
Most of the glass we use is soda-lime glass, made by heating a mixture of sand,
sodium carbonate and limestone. Borosilicate glass, made from sand and boron
trioxide, melts at higher temperatures than soda-lime glass
How are clay ceramics made?
Clay ceramics, including pottery and bricks, are made by shaping wet clay and
then heating in a furnace.
How are composites formed?
Fibres or fragments of one material (reinforcement) are surrounded by a
binder/matrix material that holds these fibres/fragments together.
E.g. fibreglass - glass fibres bound together in a polymer, used for making storage
tanks.
Outline the key points of Haber
process. Include the use of the
product.
Key stages of Haber process:
a) The purified H2
and N2
gases are passed over Fe catalyst at a high temperature (about 450 °C)
and a high pressure (about 200 atm)
b) Fe speeds up the rate of reaction, so that a lower temperature could be used in the process.
c) Some of the hydrogen and nitrogen reacts to form ammonia. N2
+ 3 H2 ⇌ 2 NH3
d) The reaction is reversible so ammonia breaks down again into nitrogen and hydrogen.
e) On cooling, the ammonia liquefies and is removed. The remaining hydrogen and nitrogen are
recycled. This means almost no material is wasted.
f) Ammonia is used for production of nitrogen-containing fertilisers.
The Haber process operates at
high T, p conditions. Explain why
this is so and why this is a
compromise.
The conditions are a compromise between rate and the yield:
• The reaction is exothermic. An optimum temperature of 450 °C is used. Using a lower temperature
would give a higher yield, but the rate of NH3
production would be too slow.
• A pressure of 200 atm is used. Using a higher pressure would give a higher yield, but would be too
expensive, because of the cost of energy to produce the high pressure
How are compounds of nitrogen, phosphorus
and potassium used?
Compounds of nitrogen, phosphorus and potassium are used as fertilisers to
improve agricultural productivity. NPK fertilisers contain compounds of all three
elements
How is industrial production of NPK fertilisers
achieved?
Ammonia can be used to manufacture ammonium salts. The ammonium sulfate, phosphate, and nitrate can be produced by reaction of ammonia with the requisite acid. 2 NH3 \+ H2SO4 → (NH4 )2SO4 2 NH3 \+ H3PO4 → (NH4 )3PO4 NH3 \+ HNO3 → NH4NO3 *nitric acid is itself made from ammonia
How is the phosphate rock utilised in the
production of fertilisers?
• Phosphate rock is reacted with nitric acid to produce phosphoric acid and
calcium nitrate.
• Phosphate rock can be reacted with sulfuric acid to produce a mixture of calcium
phosphate and calcium sulfate
• Phosphate rock can be reacted with phosphoric acid to produce calcium
phosphate.
Sources of water for drinking should be …
reliable, and they should also be free of toxic chemicals (such as heavy metals)
In the UK, water resources include …
lakes, rivers, aquifers and reservoirs.
What is an aquifer
is an underground layer of permeable rock, gravel or sand that is soaked with water
What is drilled in countries that don’t have much water
boreholes are drilled to reach water underground.
What are the solids that need to be removed from water
such as leaves and soil, must be removed
What are the three methods of sterilising water
- Chlorine is added to drinking water to sterilise it. The chlorine kills microbes - including microbes that cause potentially-fatal diseases such as typhoid, cholera and dysentery.
- Ozone, also known as O3, is a highly powerful oxidant that inactivates pesticides, fungus, organic materials, contaminates and viruses.
- Ultraviolet (UV) rays penetrate harmful pathogens in your home’s water and destroy illness-causing microorganisms by attacking their genetic core
Does the water need to be sterilised after reverse osmosis
No
What is a disadvantage of sterilising water through boiling it
- it is expensive because large amounts of energy are needed to heat the seawater/carry out reverse osmosis
- it increases the use of fossil fuels to supply the energy - which are non-renewable resources
- carbon dioxide emissions from burning fossil fuels contribute to global warming
What is the first stage of the wastewater treatment process
Screening
What is screening
This removes large objects like, diapers, nappies, sanitary items, cotton buds, face wipes Special equipment is also used to remove grit that gets washed into the sewer.
What is sedimantation
involves the separation of organic solid matter (or human waste) from the wastewater
How is sedimentation done
by putting the wastewater into large settlement tanks for the solids to sink to the bottom of the tank. The settled solids are called ‘sludge’. At the bottom of these tanks, large scrappers continuously scrape the floor of the tank and push the sludge so it can be pumped away for further treatment. The rest of the effluent water is then moved to be treated again.
What is anaerobic digestion
is a bacterial process that is carried out in the absence of oxygen. In this process the complex proteins and sugars are broken down to form more simple compounds such as water, carbon dioxide, and methane. Methane generation is a key advantage of the anaerobic process as it may be used to both heat the tank and run engines.
What is aerobic biology
is a bacterial process occurring in the presence of oxygen. Under aerobic conditions, bacteria rapidly consume organic matter and convert it into carbon dioxide. Once there is a lack of organic matter, harmful bacteria die and are used as food by other harmless bacteria.
