Topic 10 - using resources Flashcards
1
Q
what are ceramics
A
non metal solids with high melting points that arent made from carbon based compounds
2
Q
what is clay like
A
a soft material when it is dug out of the gorund so can be moulded into different shapes
when it is fired at high temperatures it hardens to form clay ceramic .
its ability to be moulded when wet and hardened makes clay ideal for making pottery and bricks
3
Q
what are two types of ceramic
A
clay
glass
4
Q
what is glass like
A
generally trnaparent
can be moulded when hot and can be brittle when thin
5
Q
whata re the two two types of glass and which is mostly made
A
soda - lime glasss (mostly made)
borosilicate glass
6
Q
how is soda lime glass made
A
made by heating a mixture of limestone, sand and sodium carbonate until it melts .
when it cools it comes out as glass.
7
Q
how is borosilicate glass made and what is it like compared to soda lime glass
A
higher melting point
made the same wat as soda lime glass using a mixture of sand and boron trioxide
8
Q
what are composites
A
made of one material embedded in another
fibres or fragments of a material are surounded by a matrix acting as a binder
the properties of a composite depend on the properties of the materials it is made from .
9
Q
what is fibreglass and what is it used for
A
consits of fibres of glass embedded in a matrix made of polymer (plastic )
it has a low density like plastic but is very strong like glass
it is used for things like skis, boats and surfboards
10
Q
what are carbon fibre composites
A
carbon fibre composites also have a polymer matrix .
the reinforcement is either made from long chains of carbon atoms bonded together (carbon fibres ) or from carbon nanotubes
these composites are very strong and light so are used in aerospace and sports car manufacturing
11
Q
what is concrete
A
made from aggregate (a mixtrure of sand and gravel ) embedded in cement
it is very strnog
this makes it ideal for use as a building material
12
Q
what is wood
A
a natural composite of cellulose fibres held together by an organic polymer matrix
13
Q
what do the prperties of poly ethene depend on
A
the catalyst that was used and the reaction conditions that it was made under
14
Q
what is low density polyethene and how is it made
A
made from ethene at a moderate temperature under high pressure
it is flexible and used for bags and bottles
15
Q
what is high density polyethene and what is it used for
A
made from ethene at low temperature and pressure with a catalyst
it is more rigid and is used for water tanks and drainpipes
16
Q
what do teh monomers a polymer is made from determne
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
17
Q
what are thermosoftening polymers and thermosetting polymers
A
thermosoftening polymers - contain individual polymer chains entwined together with weak forces between the chains , you can melt these plastics and remould them
thermosetting polymers - contain monomers that can form cross links between the polymer chains, holding the chains together in a solid structure
unlike thermosoftening polymers, these polymers do not soften when heated
they are trong hard and rigid
18
Q
what a are the properties of ceramics
A
insulators of heat and electricity
brittle
stiff
19
Q
what are properties of polymers
A
insulators of heat and electricity
can be glexible
easily moulded
have many applications including in clothing ,and insulators in electrical items
20
Q
what do the properties of composites depend on
A
the matrix / binder
and the einforcement used to make them so they have many different uses
21
Q
what are properties of metals
A
malleable
good conductors of heat and electricity
shiny
stiff
uses in electrical wires
car
body work
cutlery
22
Q
what are alloys
A
made by adding another element to the metal
thi disrupts the structure of the metal making alloys harder than pure metals
23
Q
whatare alloys of iron called and how are they made
A
steells
made by adding small amounts of carbon and sometimes other metals to iron
24
Q
how is bronze made and what is it used for
A
copper and tin
harder than copper
used to make medals, decorative ornaments nad statues
25
how is brass made and what is it used for
copper and zinc
more malleable than broxe and used in situations where lower friction is required auchas in water taps and door fittings
26
what metals are used to harden gold
zinc
copper
silver
27
what is pure gold described as
24 carat
28
what are aluminium alloys used for and why
to make aircraft
has a low density which is important in aircraft manufacture
29
what is corrosion
where metals react with substances in their environment and are gradually destroyed
30
what is the equation for the rusting of iron
iron + oxygen + water -> hydrated iron (iii) oxide
31
where on a material does corrosion happen
only on the surface where it is exposed to air
32
why does eventually all iron in an object corrode away
rust is soft crumbly solid that soon flakes of to leave more iron avialable to rusting
33
describe the corrosion of aluminium
things made by aluminium arnt completely destroyed by corrosion
this is because the aluminium oxide that forms doesnt flake away
it forms a protective layer that sticks firmly to the aluminium and stops further reactinos taking place
34
what experiment can you do to show that both oxygen and water are needed for iron to rust
if you put an iron nail in a boiling tube with just water it wont rust( the water is boiled to remove oxygen and oil is used to stop air getting in )
if you put and iron nail in a boiling tube with just air , it wont rust ( calcium chloride can be used to absorb any water from the air)
if you put and iron nail in a boiling tube with air and water it will rust
35
rusting can be prevented by coating the iron to create a barrier
what can we use to coat it
painting / coating with plastic - ideal for big and small structures alike , it can be decorative too
electroplating - this uses electrolysis to reduce metal ions onto and iron electrode . it can be used to coat the iron with a layer of a differnt meta; tthat wont be corroded away .
oiling / greasing - this has to be used when moving parts are involved like on bike chains
36
what is the sacrificial method
involves placing a more reactive metal suchas zinc or magnesium with iron
water and oxygen then react with the sacrificial metal instad of the iron
37
what does it mean when an object is galvanised
sprayed with a coating of zinc
the zinc layer is firstly protective but if its scratched the zinc around the site of the scratch works as a sacrificial metla
38
what are natural resources
include anything that comes from the earth sea or air
form without human input
39
where does rubber naturally come from and how is it mad made
naturally extracted from the sap of a tree
man made polymers have been made which replace rubber uses suchas in tyres
40
where does rubber naturally come from and how is it mad made
naturally extracted from the sap of a tree
man made polymers have been made which replace rubber uses suchas in tyres
41
what does agriculture do for natural resources
provides conditions where natural resources can be enhaced for our needs
42
what are renewable resources
reform at a similar rat to , or faster than we use them
43
what are examples of renewable resources
timber
water
food
44
what are finite resources
arent formed quickly enough to be condsidered replaceable
45
give examples of finite resources
fossil fuels and nuclear fules such as uranium and plutonium
minerals and metals found in ores
46
what happen to many finite resources once they are extracted
undergo man made processes to provide fuels and materials necessary for modern life
e.g. fractional distilation is used to produce usable roducts suchas petrol from crude oil and metal ores are reduced to produce a pure metal .
47
what are the risks of extracting finite resources
bad for the environment
uses loads of energy
scars the landscape
produces lots of waste and destroys habitats
48
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
49
we cant stop using finite resources altogether but what can cemists do
develop and adapt processes that use lower amount of finite resources and reduce damage to the environment .
e.g. chemists have developed catalysts that reduce the amount of energy required for certain industrial processes
50
how can we imporove sustainability of copper
extracting it from low grade rored (ores without much copper in (
bioleaching - bacteria are used to convert copper compounds in the ore into a soluble copper compouns , seperating out the copper from the ore in the process. the leachate (the solution produced by the process) contains copper ions which can be extracted. by electrolysis or displacement.
phytomining - involves growing plant sin soil that contians copper . the plants cant use or get rid of the copper so it gradually builds up in the leaves. the plants can be harvested , dried and burned in a furnace. the ash contains soluble copper compounds from which copper can be extracted by electrolysis or displaceent using scrap iron .
51
what are the positive effects of recycling metals
uses much less energy than is needed to mine and extract new metal
conserves the finite amount of each metal in the earth ad cuts down on the amount of waster getting sent to langfill
52
how are metals usually recycled
by melting them and then casting them into the shape of the new product
depending on what the metal wil be used for after recycling. the amount of seperation required for recyclable metals can changes.
e.eg. easte steel and iron can be kept together as they can both be addd to iron in a blast furnace to educe the amount of iron ore required
53
how can glass be recycled
glass bottles can often be reused without reshaping
other forms of glass cant be reused so they are recylced .
usually the glass is seperated by colour and chemical composition before being recycled
the glass is crushed and then melted to be reshaped for use in glass products suchas bottles or jars.
it might also be used for a different purpose suchas insulating fglass wool for wall insulation in homes.
54
what is a life cycle assesment
looks at every stage of a products life to asses the impact it would have on the environment
55
what are the four steps of life cycle assesments
1 getting the raw materials
extracting raw materials needed for a product can damage the environment
extraction can result in polution due to amount of energy needed
raw marterials often need to be processed to extract the desired materials and this often needs large amounts of energy
2. manufacture and packaging
manufacturing products and their packaging can use a lot of energy resources and can also cause a lot of pollution
you also need to think about waste products and how to dispose of them or use them
3. using the product
the use of a product can damage the environment
for example burning fuels releases greenhouse gases and other harmfull substances.
fertilisers can leech into streams causing damage to ecosystems
how long a product is used for or how many uses it get is also a factor
4 product disposal
products are often disposed in landgills
energy is used to transport waste to landfill which causes olution to be released inthe atmosphere.
proucts might be incinerated which causes air po;ution
56
compare the life cycles assessments of plastic bags and paper bags
plastic bag
raw materials
crude oil
manufacturing and packaging
the compounds needed to make the plastic are extracted from crude oil by fractional distillation , followed by cracking and then polymerisation .
wasster is reduced as the other fractions of crude oil have other uses
using th eproducts
can be reused
can be used for other things as well as shoppin for example bin liners .
product disposal
recyclable but not biodegradable and will take up space in a landfill and pollute land
Paper bag
raw materials
timber
manufacturing and packaging
pulped timber is processed using lots of energy . lots of waste is made
using the product
usually only once
product disposal
biodegradable
non toxic and can be recycled
57
what are the problems with life cycle assesments
the effect of some pollutants is harder to give a numerical value
e.g. it is difficult to apply a value to the negative visual effects of plastic bags in the environment complared to paper ones.
producing an lca isnot an objective method as it takes into account the values of the person carrying out the assesment
can be biased
selective lcas which only show some impact of a product can be writted to deliberately support claims of a company for better advertising
58
what is potable water
water that has been treated or is naturally safe for humans to drink
59
what is potable water
water that has been treated or is naturally safe for humans to drink
60
what is the difference between pure water and potable water
pure water only contains h20 molecules
potable water contains some bacteria and dissolved substances like salt
61
what is the safe ph for water
between 6.5 and 8.5
62
what type of water is rainwater
a type of fresh water
doesnt have much dissolved in it.
63
what are two places we can collect rainwaterfrom
surface water ( lakes ,rivers ,resevoirs )
groundwater ( in rocks called aquifers that trap water underground )
64
what are two places we can collect rainwaterfrom
surface water ( lakes ,rivers ,resevoirs )
groundwater ( in rocks called aquifers that trap water underground )
65
where do we get fresh water in teh uk
depends on the locatin
surface water tends to dry up first so in warm areas most of the domestice water supply comes from ground water
66
how are fresh water sources treated
filtration - a wire mesh screens out large solids and then gravel and sand beds filter out any other solid bits
sterilisation - the water is sterilised to kill any harmfull bacteria or microbes . this is done using chlorine , ozone or UV light
it is then stored and ph is monitered
67
how do dry countries get water
sea water is treated by desalination
68
how do dry countries get water
sea water is treated by desalination
69
how do you test and distill water in the lab
test the ph of the water using a ph meter . if the ph is too high or low you can neutralise it . you can do this witha titration but use a ph meter to tell you when the solutions neutral . rather than an indicator as this wont contaminate the water.
test the water for presences of sodium chloride .
do a flame test on a small sample (using nicrome wire )
if sodium ins are present the flame will turn yellow.
to test for chloride ions take another smape of water and add a few drops of dilute nitric acid and silver nitrate solution
if chloride ions are present a white precipitate will form .
to distil the water. pour the salty water into a distilation apparatus.
heat the flask
the water will boil andorm steam leaving any dissolve salts in the flask .
the steam will condense back to liquid water in the condenser and can be collected as it runs out.
then retest the distilled water for sodium chloride to chekc that it has been removed.
also retest the ph of the water witha ph meter to check that its neutral
70
what different places does waste water come from
having a bath , going to toilet , doing washing
agriculture
industrial processes
71
how is sewage treated
the sewage is screened - this involves removing any large bits of material as weell as any grit .
it is allowed to stand in a settlement tank and undergoes sedimentation - the heavier suspended solids sink to the bottom to produce sludge while the lighter effluent floats on the top .
the effluent in the settlement tank is removed and treated by biological aerobic digestion . this is when air is pumped through the water to encourage aerobic bacteria to break down organic matter - including other microbes in the water.
the sludge from the bottom of the settlement tank is also removed and transferred into large tanks . here it gets brokwn down by bacteria in a proces called anaerobic digestion .
anaerobic digestion breaks down the organic matter in the sludge , releasing methane gas in the process. the methane gas can be used as an energy source and the remaining digested waste can be used as fertiliser.
for waste water containing toxic substances , additional stages of treatment may involve adding chemicals , uv radiation or using membranes
72
what is the benefit of sewage treatment
uses less energy than the desalination of salt water
can be used in areas like singapore where ther is mot much freshwater
73
what is the chemical equation for the haber process
nitrogen + hydrogen (reversible symbol ) ammonia + heat
74
why is the haber process well suited to an industrial scale
reactants arent too dificult or expensive to obtain
75
describe the haber process
nitrogen is obtained from the air
hydrogen comes from reacting methane with steam to form hydrogen and carbon dioxide
the reactant gases are passed over an iron catalyst . a high temperature and high pressure are used
because the reaction is reversible , some of the amkkmonia produced converts back to hydrogen and nitrogen again
it eventually reaches dynamic equilibrium
the ammonia is formed as a gas
but as it cools in the condenser it liquifies and is removed. the unused hydrogend and nitrogen are recycled so nothing is wasted
the ammonia produced can then be used to make amonium nitrate
a very nitrogen rich fertiliser
76
is the forward rate of the haber proces exo or endothermic
exothermic
77
is the forward rate of the haber proces exo or endothermic
exothermic
78
what will increasing the temp f the haber proces do to equilibrium
move the equilibrium in th e wrong way -away from ammonia and towards nitroged andhydrogen so the yield of ammonia will be greater at lower temps
however low temps means slower rate of reaciton
79
what is the best temp for haber process
450 degrees
80
what will higher pressures do to the position of equilibrium in the haber process
move it towards the products since there are four molecules of gas on the left hand side for every two molecules on the right . so increasing pressure maximises the percentage yield. it also increase the rate of reation
81
what catalyst is used to make the haber process quicker
iron catalyst
82
what natural substance do farmers use to fertilise fields and why are formulated fertilisers better
manure
formulated fertilisers are more widely available, easier to se, dont smell , enoigh nutrients
83
what are the three main elements in fertilisers
nitrogen , phosphorous and potasssium
84
what are npk fertilisers
formulations containing salts of nitrogen , phosphorous and pottasium in the right percentages of the elements
85
how can nitric acid be made
reacting ammonia with oxygen and water
86
how can you make ammonium salts
reacting ammonia with acids
87
what does ammonia and nitric acid react together to produce
ammonium nitrate
88
how is ammonium nitrate made in industry and in the lab
industry :
the reaction is carried out in giant vats , at high concentrations resulting in a very exothermic reaction . the heat released is used to evaporate water from the mixture to make a very concentrated ammonium nitrate product.
in the lab :
te reactino is carried out on a much smaller scale by titration and crystallisation
the reactants are at a much lower concnetration than in industry so less heat is produced by the reaction and it is sager for a person to cary out.
after the titration , the mixture then needs to be crystalised to give pure ammonium nitrate crystals .
crystallisation isnt used in industry because it is very slow.
89
what two things can be mined and used as a source of potassium
potassium chloride
potassim sulphate
90
what is the issue with phosphate rocks and what do we do to solve this
insoluble so plants cant use the phosphate slas as nutrients
reactino with nitric acid produces phosphoric acid and calcium nitrate.
reaction with sulfuric acid produces calcium sulfate and calcium phosphate (this is known as single superphosphate )
reaction with phosphoric acid only produces calcium phosphate
the production of this reaction is called (triple superphosphate )
