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c9 the earths resources Flashcards

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1
Q

what are natural resources?
where do they come from?

A

1) resources that form without any human input. some of the products made from natural resources can be replaced by synthetic products or improved upon by man made processes.
2) the earth, sea and air

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2
Q

what are renewable resources?
examples?

A

1) resources that reform at a similar rate to, or faster than we use them.
2) an example is timber as trees can be planted following a harvest and only take a few years to grow.
3) fresh water

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3
Q

what are finite resources?
examples?

A

1) resources that arent formed quickly enough to be considered replaceable.
2) some examples are fossil fuels, nuclear fuels (such as uranium and plutonium), minerals and metals found in ores.

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4
Q

what happens to many finite resources after they’ve been extracted?
examples?

A

they undergo man-made processes to provide fuels and materials necessary for modern life.
- eg: crude oil undergoing fractional distillation to produce petrol.
- eg: metal ores being reduced to pure metal

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5
Q

what must people bear in mind when extracting raw finite resources?

A

1) they have to balance out: social, economic and environmental effects of extraction.

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6
Q

how can we improve the sustainability of copper?

A

extracting copper from low-grade ores:

1) bioleaching
2) phytomining

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7
Q

what is sustainable development?

A

an approach to development that takes into account the needs of present society, while not damaging the lives of future generations

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8
Q

in what ways can resources not be sustainable?

A

1) using them
2) extracting them due to the amount of energy used and waste produced.
3) processing resources into useful materials due to the energy used and the fact that they’re made from finite resources

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9
Q

how does biobleaching work?

A

1) bacteria is used to convert copper compounds in the ore into soluble copper compounds, extracting the copper in the process.
2) the leachate contains copper ions which can be extracted by electrolysis or displacement with scrap iron

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10
Q

how does phytomining work?

A

1) involves growing plants in soil that contains copper.
2) the plants cant use or get rid of the copper so it gradually builds up in the leaves.
3) the plants can be harvested, dried and burned in a furnace.
4) the ash containing the soluble copper compounds can be electrolysed or displaced to extract the soluble copper compounds

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11
Q

how are metals usually recycled?

A

1) by melting them and then casting them into the shape of a new product
- depending on what the metal will be used for after recycling, the amount of separation required for recyclable metals can change

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12
Q

what are some disadvantages and advantages to recycling metals?

A

DISADVANTAGES-
1) the process is slow

ADVANTAGE-
1) uses much less energy than mining for metals.
2) conserves the finite resources
3) reduces the amount of waste getting sent to landfill

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13
Q

how can glass be recycled?

A

1) the glass is separated by colour and chemical composition before being recycled.
2) the glass is then crushed and then melted to be reshaped for use in glass products such as bottles or jars.
3) it can also be used for insulating glass wool insulation in homes

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14
Q

what is the life cycle assessment?

A

an assessment that looks at the stage of a products life to assess the impact it would have on the environment.

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15
Q

what are the different stages that need to be considered in the LCA?

A

1) getting the raw materials
2) manufacturing and packaging
3) using the product
4) product disposal

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16
Q

what could selective or abbreviated LCA be devised to do?

A

to evaluate a product. however these can be misused to reach a predetermined conclusion. eg in support of claims for advertising purposes

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17
Q

what is the LCA for a plastic bag?

A

1) RAW MATERIALS:
- crude oil

2) MANUFACTURING & PACKAGING:
- compounds needed to make the plastic bag are extracted by fractional distillation. followed by cracking and then polymerisation

3) USING THE PRODUCT:
- can be reused. used as shopping bags or bin liners.

4) PRODUCT DISPOSAL:
- recyclable but not biodegradable and will take up space in a landfill

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18
Q

what is the LCA for a paper bag?

A

1) RAW MATERIALS:
- timber

2) MANUFACTURING & PACKAGING:
- pulped timber is processed using lots of energy. lots of waste is made.

3) USING THE PRODUCT:
- usually only used once

4) PRODUCT DISPOSAL:
- biodegradable, non toxic and can be recycled

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19
Q

problems with LCAs?

A

1) the effect of pollutants is harder to give a numerical value to.
2) they can be biased as it takes into account the values of the person carrying out the assessment.
3) selective LCAs only show some of the impacts of a product on the environment, they can also be biased as they can be deliberately written to support the positive claims of a company.

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20
Q

what is potable water?

A

water that has been treated or is naturally safe for humans to drink- its essential for life

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21
Q

is potable water also pure?

A

no it wouldnt be considered pure because pure water contains only H2O molecules. whereas potable water contains many other dissolved substances

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22
Q

what are two ways in which you can collect water when it rains?

A

1) collect it as surface water (lakes, rivers ect)
2) collect it as groundwater (in rocks underground called aquifers that trap water underground)

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23
Q

how to treat rain water to make it potable?

A

1) filtration with a wire mesh which screens out large solids.
2) sand beds which also filter out large solids.
3) sterilisation which kills any harmful bacteria or microbes. (using chlorine gas, UV lights or ozone)

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24
Q

how to treat sea water to make it potable?

A
  • desalination using distillation to evaporate out the water.
  • reverse osmosis where the salty water is passed through membranes that only allows water molecules to pass through. ions and larger molecules are trapped by the membrane.

BOTH METHODS REQUIRE A LOT OF ENERGY AND ARE THEREFORE EXPENSIVE AND NOT PRACTICAL TO PRODUCE LARGE QUANTITIES

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25
Q

how to treat sewage treatment?

A

1) the sewage is screened- removing any large solids.
2) sedimentation- sewage stands in a settlement tank. the bottom= sludge & top= effluent.
3) effluent is treated by biological aerobic digestion to break down any organic matter.
4) sludge is treated by anaerobic digestion to break down organic matter, releasing methane which can be used as an energy source. remaining waste can be used as a fertiliser.
5) waste water containing toxic substances may undergo adding chemicals, UV radiation or membranes

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26
Q

what is the haber process?
what is the equation to make ammonia?
Pros of this reaction?

A

1) it is the process in which ammonia is formed.
2) N2 + 3H2 —> 2NH3

3) well suited for an industrial scale as the reactants arent too difficult or expensive

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27
Q

how does the haber process work?

A

1) the reactant gases are passed over an iron catalyst at a temperature of 450 degrees and a pressure of 200 atmospheres.
2) the reactants then react to form ammonia and are condensed out

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28
Q

what can happen due to the fact that the haber process is a reversible reaction?

A

some of the ammonia produced coverts back to hydrogen and nitrogen. it eventually reaches a dynamic equilibrium

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29
Q

what is a use of ammonia?

A

used to make ammonium nitrate - a very nitrogen rich fertiliser

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30
Q

where is nitrogen and hydrogen obtained?

A

NITROGEN: air (78% of air is nitrogen)
HYDROGEN: reacting methane with steam to form hydrogen and carbon dioxide.

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31
Q

what type of reaction is the haber process?
so what would happen if the temperature is increased?
but why is a lower temperature bad for the haber process?

A

1) an exothermic reaction
2) the equilibrium would shift the wrong way
3) because although a lower temp would increase the yield of ammonia, it does mean that there would be a slower rate of reaction, so equilibrium would be reached more slowly

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32
Q

so what is the compromise of temperature for the haber process?

A

450 degrees is the compromise between the maximum yield and the speed of the reaction

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33
Q

how does pressure effect the haber process?

A

1) higher pressure shifts the equilibrium towards the products since there are 4 molecules pf gas on the left side for every 2 molecules on the right.
2) so increasing the pressure also increases the yield and the rate of reaction

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34
Q

what is the compromise for pressure in the haber process?

A

the pressure is set as high as possible without making it too expensive or too dangerous to maintain. 200 atmospheres

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35
Q

what catalyst is added to the haber process (but doesnt affect the yield) ?

A

an iron catalyst

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36
Q

how do farmers fertilise land?

A

farmers use manure to fertilise fields as they are more widely available, easier to use, dont smell and have just enough of each nutrient so more crops can be grown

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37
Q

what are the 3 essential nutrients in fertilisers?

A

nitrogen, phosphorus and potassium

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38
Q

what do fertilisers do?

A

they replace the elements , or provide more of them.
this helps to increase crop yield, as the crops can grow faster and bigger

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39
Q

what are NPK fertilisers?

A

fertilisers containing salts of nitrogen, phosphorus and potassium in the RIGHT percentages

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40
Q

what can ammonia be used to produce?
examples?

A

1) nitrogen- containing compounds
- ammonia could be reacted with oxygen and water to make nitric acid.
- ammonia could be reacted with a series of acids to get ammonium salts for fertilisers.
- ammonia and nitric acid can react together to form ammonium nitrate, very good fertiliser

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41
Q

how can a fertiliser such as ammonium nitrate be made in the industry?

A

1) the reaction of ammonia and nitric acid is carried out in giant vats, at high concentrations, resulting in a very exothermic reaction.
2) the heat released is used to evaporate water from the mixture to make a very concentrated ammonium nitrate product.

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42
Q

how can a fertiliser such as ammonium nitrate be made in the industry?

A

1) the reaction is carried out in a smaller scale by titration and crystallisation.
2) the reactants are at much lower concentration than in the industry, so less heat is produced by the reaction and it is safer for a person to carry out.
3) after the titration, the mixture then needs to be crystallised to give pure ammonium nitrate crystals.
4) crystallisation isnt used in the industry as it is very slow

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43
Q

where are phosphate and potassium sourced?

A

-from mined compounds

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44
Q

what compounds of potassium can be mined as a source of potassium?

A

-potassium chloride and potassium sulphate

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45
Q

what can be mined for phosphate?

A

phosphate rock can be mined. however, because the phosphate salts in the rock are insoluble, plants can directly absorb them and use them as nutrients

46
Q

what reactions with phosphate rock can produce soluble phosphates?

A
  • nitric acid produces phosphoric acid and calcium nitrate.
  • sulphuric acid produces calcium sulphate and calcium phosphate.
  • phosphoric acid only produces calcium phosphate
47
Q

what are ceramics?

A

non metal solids with high melting points that arent made from carbon-based compounds

48
Q

what are some ceramics made out of?
where is this material made from?
what is it ideal for?

A

1) clay
2) dug up from the ground so it can be moulded into different shapes
3) making pottery and bricks

49
Q

what happens to clay once it is fired at high temperatures?

A

it hardens to form clay ceramics

50
Q

what is a transparent example of ceramics?
what are its properties in heat and thickness?

A

1) glass
2) it can be moulded in heat but it is brittle when thin.

51
Q

what is most glass made out of?

A

1) by heating limestone, sand and sodium carbonate until it melts.

52
Q

what is borosilicate glass made out of?

A

it is made using a mixture of sand and boron trioxide but it has a higher melting point

53
Q

what are most composites made from?

A

two materials, a matrix or binder
surrounding and binding together fibres or fragments of the other
material, which is called the reinforcement.

54
Q

what does fibreglass consist of?
what are its properties?

A

consists of fibres of glass embedded in a matrix made of polymer.
- it has a low density, but it is very strong.
- however it can be used for things like skis, surfboards and boats.

55
Q

what does carbon fibre consist of?
what are it’s properties?

A

consists of polymer matrix, the reinforcement is either made from long chains of atoms bonded together

56
Q

describe phase 1- volcanoes gave out gases

A

1) for the first billion years, the earth was quite explosive- the surface was covered in active volcanoes which released a lot of gases.
2) this is believed to have formed the early atmosphere.
3) the early atmosphere was probably made up of CO2, with virtually no O2.
4) volcanic activity also released nitrogen which built p in the atmosphere over time. aswell as water vapour, methane and ammonia.

57
Q

describe phase 2- oceans, algae and green plants absorbing CO2.

A

1) when the water vapour condensed, it formed the oceans.
2) lots of CO2 was removed from the early atmosphere as it dissolved in the oceans.
3) this dissolved CO2 went through a series of reactions to form carbonate precipitates that formed sediments on the seabed.
4) when marine animals evolved, their shells and skeletons contained some of these carbonates from the oceans.
5) green plants and algae evolved and absorbed some CO2 so they could carry out photosynthesis

58
Q

how was some carbon trapped in rocks and fossil fuels when organisms died?

A

1) when plants, plankton and marine animals die, they fall onto the seabed and get buried under layers of sediment.
2) over a million years, they become compressed and form sedimentary rocks, oil and gas.
3) this traps the carbon within them.
4) this is how things like coal, crude oil and natural gas that are made by this process are called ‘fossil fuels’.

59
Q

how are natural gases and crude oil formed?

A

from deposits of plankton

60
Q

what is coal?

A

a sedimentary rock made from thick plant deposits

61
Q

what is limestone?

A

a sedimentary rock made from calcium carbonate deposits from the shells and skeletons of marine organisms

62
Q

describe phase 3- green plants and algae produced oxygen

A

1) algae evolved first about 2.7 billion years ago.
2) the over the next billion years, green plants also evolved.
3) as oxygen levels built up in the atmosphere over time, more complex life could evolve.
4) eventually, around 200 million years ago, the atmosphere reached a composition similar to how it is today

63
Q

what is the earth’s composition today?

A

80% nitrogen
20% oxygen
other gases making up less that 1% of the atmosphere: CO2, noble gases and water vapour

64
Q

what are examples of greenhouse gases?

A

carbon dioxide
methane
water vapour

65
Q

what do greenhouse gases do?

A

they act like an insulating layer in the earths atmosphere which helps the earth to be warm enough to support life

66
Q

what do greenhouses absorb and dont absorb?

A

they dont absorb the incoming short wavelength from the sun. but they do absorb the long wavelength that gets reflected back off the earth

67
Q

what is the greenhouse effect?

A

when the earth gets warmer due to the longwave radiation because it is thermal radiation

68
Q

what are some forms of human activity which affect the amount of greenhouse gases in the atmosphere?

A

1) deforestation- fewer trees means less CO2 from the atmosphere via photosynthesis.
2) burning fossil fuels- carbon that was trapped in these fuels is released as CO2.
3) agriculture- more farm animals produce more methane through their digestive processes.
4) creating waste- more landfill sites and more waste from agriculture means more CO2 and methane released by decomposition of waste

69
Q

how is increasing CO2 levels linked to climate change?

A

1) in recent years the earths surface temperature has been increasing in greater amounts.
2) it is believed that the release of CO2 from increased human activity is causing this increase.
3) as CO2 is a greenhouse gas and traps and re-radiates wavelengths back to earth.
4) some of the media is biased though

70
Q

what are some of the consequences of climate change?

A

1) an increased temp means ice caps melting- rise in sea levels and increased coastline floods.
2) changes in rainfall may lead to some areas getting too much or too little water. changing their ability to growing crops for food.
3) the frequency and severity of storms may increase.
4) changes of temp and water available in habitats may affect wild species, leading to differences in distribution

71
Q

what are carbon footprints?

A

a measure of how much CO2 and other greenhouse gases are released over the full life cycle of something.
- eg a service, an event or product

72
Q

what is the downside of the carbon footprint?

A

it is very hard to measure- or even impossible.
- this is because of the many different factors that must be considered, eg: counting emissions released as a result of manufacturing all the parts. when u use it. and the disposal

73
Q

why is a rough calculation of carbon footprints still useful though?

A

people get a good idea of what the worst emitters are, so they can avoid them

74
Q

what are different methods of reducing greenhouse gases and intern, reducing carbon footprints?

A

1) using renewable sources of energy or nuclear energy instead of fossil fuels.

2) using more efficient processes could conserve energy and cut waste. as lots of waste decomposes to release methane, it lowers methane emissions.

3) gov taxing companies or individuals based on the amount of greenhouse gases they emit.

4) gov can put a cap on emissions of all greenhouse gases that companies make, then sell licenses for emissions up to that cap

75
Q

why is it difficult to reduce carbon footprints? pt 1

A

1) theres still a lot of work to be done on alternative technologies that result in lower CO2 emissions eg:
- many renewable technology eg solar panels are quite expensive. more development should make them cheaper, so they can be used more widely.

2) individuals in developed countries need to make changes to their lifestyles eg:
- choosing to cycle or walk rather than using a car.
- reducing air travel use.
- doing anything that saves energy at home such as turning heating down

and it could be hard to get ppl to make changes if they dont want to and are uneducated on the reasons behind the change

76
Q

why is it difficult to reduce carbon footprints? pt 2

A

1) a lot of govs believe that making changes to reduce CO2 emissions could have an impact on economic growth in their country - which could be bad for people’s wellbeing. esp in developing countries.

2) it is hard to make international agreements to reduce emissions as most countries will not risk their economic development if they think others wont do the same.

77
Q

1) what are particulates made up of?
2) what can problems can particulates from incomplete combustion lead to?

A

1) soot, unburned hydrocarbons released, carbon monoxide.
2) if they are inhaled, then can get stuck in your lungs and cause damage, leading to respiratory problems.
3) they’re bad for the environment as they reflect sunlight back into space, leading to global dimming

78
Q

what problems does carbon monoxide cause?

A

1) can be rlly dangerous as it can stop your blood from carrying oxygen around the body.
- it binds to the haemoglobin in your blood so less oxygen is transported.
- a lack of oxygen in the blood can lead to fainting, a coma, or even death.
2) it is colourless and odour, this makes it even more dangerous as it is hard to detect

79
Q

what is released during the combustion of fossil fuels?

A

sulfur dioxide, that contain sulfur impurities- the sulfur in the fuel becomes oxidised
- respiratory problems

80
Q

what is created from a reaction between oxygen and nitrogen in the air, caused by the heat of burning?

A

nitrogen oxides
- respiratory problems

81
Q

what happens with sulfur dioxide and nitrogen oxide mixing with water in clouds?

A

they form dilute sulfuric and nitric acid. this then falls as acid rain

82
Q

what is the problem with acid rain?

A

1) kills plants
2) damages buildings and statues
3) corrodes metal

83
Q

how to test for sulfur impurities in a fuel?

A

bubbling the gases from combustion through a universal indicator solution. positive= gases will contain SO2 which will form sulfuric acid and turn the indicator red

84
Q

what are steels and how are they made?

A

they’re alloys of iron and they’re made by adding small amounts of carbon and sometimes other metals into pure iron

85
Q

what are types of steel?
their properties?
their uses?

A

1) low carbon steel (0.1- 0.3%),
easily shaped, used for car bodies.
2) high carbon steel (0.22- 2.55%)
, very hard and inflexible, used for blades for cutting tools and bridges.
3) stainless steel (added chromium and sometimes nickel), corrosion resistant, used for cutlery and containers for corrosive substances

86
Q

what is bronze?
what is it used for?

A

1) bronze= copper + tin.
- bronze is harder than copper.
- its used to make medals, decorative ornaments and statues.

87
Q

what is brass?
what is it used for?

A

1) brass= copper + zinc.
- brass is more malleable than bronze.
- used in situations where lower friction is required, eg water taps and door fittings.

88
Q

what are the properties of pure gold?
how is this fixed?
what is pure cold described as?
what are gold alloys used for?

A

1) very soft
2) gold alloys using zinc, copper and silver.
3) 24 carat gold
4) making jewellery

89
Q

what are the properties of aluminium?
how is this fixed?
what can aluminium alloys be used for?

A

1) low density but too soft
2) making alloys of it with smaller amounts of metals.
3) used to make an aircraft because it has low density and thats an important property in aircraft manufacture

90
Q

what is corrosion?

A

where metals react with substances in their environment and are gradually destroyed

91
Q

what happens to rust easily?
what are the conditions for iron to rust?

A

1) iron corrodes easily, it rusts.
2) the conditions are: it must be in contact with both oxygen and water, which are present in air.

92
Q

what is the compound of rust called?

A

hydrated iron (III) oxide

93
Q

where does corrosion take place?

A

1) on the surface of a material, where its exposed to the air.
- unfortunately, rust is soft and crumbly and eventually flakes off, leaving more iron available to rust again

94
Q

what other element corrodes in air but how is it slightly different to iron?
why?

A

aluminium, however unlike iron, it doesnt get completely destroyed by corrosion.
- this is because when aluminium corrodes, it doesnt flake away. instead it forms a protective layer that firmly sticks to the aluminium below and stops any further reaction from taking place

95
Q

what experiment can be used to prove that water alone is not enough to cause iron to rust?

A

1) put an iron nail in a boiling tube with just boiling water.
- the water is boiled to remove oxygen, the oil is used to stop air from getting in.

96
Q

what experiment can be used to prove that oxygen alone isnt enough to cause iron to rust?

A

1) put an iron nail in a boiling tube with just oxygen.
- calcium chloride can be used to absorb any water from the air

97
Q

what happens to the mass of an iron nail when it gets rusty?

A

it increases because the iron atoms in the nail have now bonded to oxygen and water, resulting in a compound which is heavier than iron alone

98
Q

what are different ways of coating iron or making a barrier to prevent rusting?

A

1) coating with plastic- ideal for structure sizes, can also be decorative.
2) electroplating- using electrolysis to reduce metal ions onto an iron electrode. this can be used to coat the iron with a layer of a different metal that wont be corroded away.
3) greasing/ oiling- this has to be used when moving parts are involved

99
Q

what is the sacrificial method in reducing rusting?

A

this involves placing a more reactive metal, such as zinc or magnesium, with the iron.
- water and oxygen react with the sacrificial metal instead of the iron

100
Q

what is galvanising?

A

spraying an object with a coating of zinc.
- the zinc layer is firstly protective, but if its scratched, the zinc around the site of he scratch works as a sacrificial metal

101
Q

what 2 things can influence the properties of a polymer?

A

how its made and what its made from

102
Q

what does the properties of poly(ethene) depend on?

A

the catalyst that was used and the reaction conditions (temperature and pressure)

103
Q

1) how is low density poly(ethene) made?
- whats it used for?

2) how is high density poly(ethene) made?
- whats it used for?

A

1) ethene at a moderate temperature and under a high pressure.
- its flexible and used for bags and bottles.

2) ethene but a lower temperature and pressure with a catalyst.
- rigid and is used for drainpipes and water tanks

104
Q

what do the monomers that a polymer is made from determine?

A

the type of bonds that form between the polymer chain.
- these weak bonds between the different molecule chains determine the properties of the polymer

105
Q

thermosetting polymers

A

contain monomers that can form crosslinks between the polymer chains, holding the chains together in a solid structure.
- they do not soften when heated.
- they are strong, hard and rigid

106
Q

thermosoftening polymers

A

contain individual polymer chains entwined together with weak forces between the chains.
- they soften when heated and they are mouldable

107
Q

ceramics and their properties

A
  • include glass and clay ceramics such as porcelain and brick.
  • they’re insulators of heat and electricity, brittle and stiff
108
Q

what are the properties of composites dependent on?

A

the matrix/ binder and the reinforcement used to make them, so they have many different uses

109
Q

properties of polymers?
how can they be used?

A
  • insulators of heat and electricity.
  • they can be flexible.
  • easily moulded.

they have many applications including in clothing and insulators in electrical items

110
Q

properties of metals?
how can they be used?

A

-malleable
- good conductors of heat and electricity
- ductile
- shiny and stiff

they can be used in electrical wires, car bodywork and cutlery

chemistry spec (9 decks)

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