Topic 10- Using Resources Flashcards
1
Q
what do Humans use the Earth’s resources for
A
to provide warmth, shelter, food
and transport.
2
Q
what do Natural resources, supplemented by agriculture do
A
provide food, timber,
clothing and fuels.
3
Q
how are clay ceramics, including pottery and bricks made
A
by shaping wet clay and then heating in a furnace.
4
Q
how is soda lime glass made
A
by heating mixture of sand, sodium carbonate and limestone
5
Q
what is Borosilicate glass
A
made from sand and boron trioxide, melts at higher temperatures than soda-lime glass.
6
Q
what do the properties of polymers depend on
A
-what monomers they are made
from
-conditions under which they are made.
For example, low density (LD) and high density (HD) poly(ethene) are produced from
ethene.
7
Q
what are composites
A
made of one material embedded in another. Fibres or fragments of a material (known as the reinforcement) are surrounded by a matrix acting as a binder
8
Q
what do the properties of a composite depend on
A
the properties of the materials it is made from
9
Q
give some examples of composites
A
fibre glass, carbon fibre, concrete, wood
10
Q
what is fibre glass?
A
- consists of fibres of glass embedded in a matrix made of polymer (plastic)
- low density (like plastic) and strong (like glass)- used for skis boats and surfboards
11
Q
what is carbon fibre
A
- have polymer matrix
- reinforcement is made from long chains of carbon atoms bonded together (carbon fibres) or from carbon nanotubes
- strong and light- aerospace and sports car manafacturing
12
Q
what is concrete
A
- made from aggregate (sand and gravel) embedded in cement
- strong- building materials (skate parks)
13
Q
what is wood
A
natural composite of cellulose fibres held together by an organisc polymer matrix.
14
Q
How is low density poly(ethene) made?
A
from ethene moderate temperature high pressure with a catalyst flexible- used for bags and bottles
15
Q
how is high density poly(ethene) made?
A
from ethene lower temp lower pressure different catalyst more rigid- used for water tanks and drain pipes
16
Q
what do the monomers that a polymer is made form determine?
A
the type of bonds that form between the polymer chains
these weak bonds between the different molecule chains determine the properties of the polymer
17
Q
what are thermosoftening polymers
A
- contain individual polymer chains entwined together
- weak forces between the chains
- can melt them and remould them
18
Q
what are thermosetting polymers?
A
- contain monomers that can form cross-links between the polymer chains, holding the chains together in a solid structure
- don’t soften when heated.
- strong, hard and rigid
19
Q
give some properties of ceramics
A
- include glass and clay ceramics such as porcelain and bricks
- insulators of heat and elec
- brittle and stiff
20
Q
what are ceramics
A
non metal solids with high mp that aren’t made from carbon-based compounds
21
Q
give properties of polymers
A
- insulators of heat and elec
- flexible
- easily moulded
- clothing and insulators in electrical items.
22
Q
give properties of composites
A
depend on the matrix/binder and reinforcement used to make them- so have many different uses
23
Q
properties of metals
A
malleable
good conductors of heat and electricity, ductile (drawn into wires)
shiny
stiff
electrical wires, car body-work and cutlery
24
Q
how are alloys made
A
by adding another element to the metal- this disrupts the structure of the metal, making it a harder material
25
how is steel made
by adding small amounts of carbon and sometimes other metals to iron.
26
what is bronze and what is it used for
copper & tin
bronze is harder than copper
used to make medals, ornaments and statues
27
what is brass and what is it used for
copper & zinc
more malleable than bronze and is used in situation where lower friction is required, such as in water taps and door fittings.
28
what is used to make jewellry
gold alloys
pure gold = soft
SO metals such as zinc copper and silver are used to harden the gold.
pure gold = 24 carat, so 18 carats = 18/24 parts are pure gold (75%)
29
what is used for aircraft
aluminium alloys
-low density
pure aluminium is too soft- so alloyed to make it stronger with other metals
30
what is corrosion
destruction of materials by chemical reactions with
| substances in the environment.
31
what is an example of corrosion
iron rusting- both air and water are necessary for iron to rust
32
what is rust
hydrated iron(lll) oxide
iron + oxygen + water -> hydrated iron(lll) oxide
33
where does rusting happen
on the surface of a material where it's exposed to the air
34
how does rusting occur
when the soft crumbly rust flakes off, more iron is left to rust away again- leading to corrosion
35
why isn't aluminium completely destroyed by corrosion
Aluminium has an oxide coating that protects the metal from further corrosion.
36
what is the experiment that shows both oxygen and
| water are needed for iron to rust?
1) iron nail in boiling tube with just water- no rust (boiled water removed o2)
2) iron nail in boiling tube with just air- no rust (calcium chloride can be used to absorb any water from the air)
3) iron nail in boiling tube with air + water- RUST!
37
how can rusting be prevented
painting/coating with plastic- ideal for big and smaller structures alike
electroplating- electrolysis is used to reduce metal ions onto and iron electrode; can be used to coat iron with a layer of a different metal that wont be corroded away.
oiling greasing- when moving parts are involved (eg. bike chain)
38
what is a sacrificial method
placing more reactive metal (such as zinc or magnesium) with the iron.
water and oxygen then react with the metal instead of with the iron.
39
explain a technique for prevention of rusting that involves both methods
OBJECT can be galvanised by spraying it with a coat of zinc.
protective & if scratched, zinc with work as a sacrificial method.
40
what are natural resources?
form without human input
come from earth,sea or sky
can be replaced or improved by man made products eg. rubber is extracted from sap of a tree, however man made polymers have now been made- replace rubber in eg. tyres
agriculture provides ideal conditions eg. fertilizers increase yield
41
give an example of a renewable resource
timber- only takes a few years to regrow
fresh water and food
42
what are finite resources
non renewable, aren't formed quickly enough to be considered replaceable
43
give examples of finite resources
fossil fuels, nuclear fuels (uranium and plutonium)
minerals and metals found in ores
44
what often happens after finite resources have been extracted?
undergo man-made processes- provides fuels and materials necessary for modern life.eg. fractional distillation- produces petrol from crude oil
metal ores are reduced to form pure metal.
45
why do extracting finite resources have risks?
people have to balance the social, economic and environmental effects of extracting finite resources
eg. mining metal ores = good, useful products can be made, provides jobs, brings in money
however = bad, uses loads of energy, scars the landscape, produces lots of waste & destroys habitats.
46
what is sustainable development?
approach that considers present society and future generations
47
what is the situation with metal ores
The Earth’s resources of metal ores are limited.
48
whats happening to copper ores?
becoming scarce and new ways of extracting copper
from low-grade ores include phytomining, and bioleaching. These methods avoid traditional mining methods of digging, moving and disposing of large amounts of rock.
49
what is phytomining
uses plants to absorb metal compounds. The plants
| are harvested and then burned to produce ash that contains metal compounds.
50
what is bioleaching
uses bacteria to produce leachate solutions that contain metal compounds.
51
how can the metal be obtained?
The metal compounds can be processed to obtain the metal.
For example, copper can be obtained from solutions of copper compounds by displacement using scrap iron or by electrolysis.
52
what does recycling do for energy
uses much less, conserves finite amount of each metal in the earth and cuts down on the amount of waste getting send to landfill.
53
how are metals usually recycled?
by melting, and then casting
54
what does glass recycling do for the environment?
helps sustainability by reducing the amount of enegy needed to make new glass products, and also the amount of waste created when glass is thrown away.
55
how can glass be recycled
1) often can be reused without reshaping.
2) separated by colour and chemical composition before recycling.
3) crushed & melted to be reshaped for use in bottles/ jars etc. OR insulating glass wool for wall insulation in homes.
56
what are 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.
57
why is LCA is not a purely objective process?
Use of water, resources, energy sources and production of some wastes can be fairly easily quantified. Allocating numerical values
to pollutant effects is less straightforward and requires valuejudgements
58
how can LCAs be biased?
Selective or abbreviated LCAs can be devised to evaluate a product
but these can be misused to reach pre-determined conclusions
eg in support of claims for advertising purposes.
59
what are the features shown in plastic bags in an LCA
crude oil
| compounds are extracted from crude oil by fractional distilation
60
what are 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.
61
why is LCA is not a purely objective process?
Use of water, resources, energy sources and production of some wastes can be fairly easily quantified. Allocating numerical values
to pollutant effects is less straightforward and requires valuejudgements
62
how can LCAs be biased?
Selective or abbreviated LCAs can be devised to evaluate a product
but these can be misused to reach pre-determined conclusions
eg in support of claims for advertising purposes.
63
what are the features of plastic bags in LCAs?
crude oil
compounds are extracted from crude oil by fractional distillation, cracking then polymerisation- LITTLE WASTE (other fractions have other uses)
can be reused- shopping, bin liners etc
recyclable but NON biodegradable- landfill & pollution
64
what are the features of paper bags in LCAs?
timber
pulped timber is processed using lots of energy- LOADS OF WASTE
usually only used once
biodegradable, non-toxic and can be recycled.
65
what is ideal drinking water like?
sufficiently low levels of dissolved salts and microbes
66
what is potable water
Water that is safe to drink
67
is potable water pure
not pure water in the chemical sense because it contains dissolved substances.
68
what do the methods used to produce potable water depend on
available supplies of water and local conditions.
69
how can sewage be treated?
1) sewage is screened- removes large bits & grit
2) sedimentation- heavy sludge at bottom light effluent at top
3) effluent removed and treated by biological aerobic digestion- air pumped through water to encourage aerobic bacteria to break down organic matter.
4) sludge is removed- transferred to large tanks- broken down by anaerobic digestion
5) methane gas is release by this which can be used as an energy source and the remaining digested waste can be used as a fertiliser
FOR WASTE WATER CONTAINING TOXIC SUBSTANCES... ADD CHEMICALS, UV RAD, OR USING MEMBRANES
70
name some sterilising agents used for potable water?
chlorine, ozone or
| ultraviolet light.
71
what is ammonia made from and what is it used for?
THE HABER PROCESS
nitrogen (n2) + hydrogen (3H2) == ammonia (2NH3)
(+ heat)
used to make ammonium nitrate- a very nitrogen-rich fertiliser.
72
where does waste come from?
Urban lifestyles and industrial processes produce large amounts of waste water
these require treatment before being released into the
environment.
organic matter and harmful microbes are in sewage and agricultural waste, so need to be removed.
Industrial waste water may require removal of organic matter and harmful chemicals.
73
how can sewage be treated?
1) sewage is screened- removes large bits & grit
2) sedimentation- heavy sludge at bottom light effluent at top
3) effluent removed and treated by biological aerobic digestion- air pumped through water to encourage aerobic bacteria to break down organic matter.
4) sludge is removed- transferred to large tanks- broken down by anaerobic digestion
5) methane gas is release by this which can be used as an energy source and the remaining digested waste can be used as a fertiliser
WASTE WATER CONTAINING TOXIC SUBSTANCES... ADD CHEMICALS, UV RAD, OR MEMBRANES
74
when is sewage treatment most effective?
- requires more processes that treating fresh water, but uses less energy than desalination of salt water
- could be used in areas with not much fresh water
eg. singapore is treating waste water and delivering it back into water supplies
people don't like idea though
75
which way is exothermic in the haber process?
forwards
76
how is nitrogen obtained?
easily from the air- (78% nitrogen)
77
how is hydrogen obtained?
reacting methane (from natural gas) with steam to form hydrogen + CO2
78
what is the pressure like for the haber process?
higher pressure moves the equilibrium where there are fewer moles, and there are fewer moles on the right, so we use a high pressure to produce as much ammonia as possible.
it also increases ROR
200 atmospheres (high but not too expensive)
79
what temperature would be ideal for the haber process?
LOW TEMP
WHY?
if you increase the temp, the equilibrium will move to the left (endo) so therefore if you decrease the temp, the equilibrium will move to the right (exo) so more ammonia will be produced
80
what is the actual temp of ammonia production and why?
a low temp= low ROR
SO a compromise is made btween yield and speed...
450 degrees
81
what is the pressure like for the haber process?
higher pressure moves the equilibrium where there are fewer moles, and there are fewer moles on the right, so we use a high pressure to produce as much ammonia as possible.
it also increases ROR
82
what catalyst is used and what affect does it have on the yield?
iron catalyst, doesn't affect the yield
83
why are formulated fertilisers better than manure?
widely available, easier, don't smell, enough nutrients
84
Which 3 elements are used in NPK fertilisers?
Nitrogen, phosphorus, and potassium (hence NPK)
85
how can industrial production of NPK fertilisers be achieved
using a variety
of raw materials in several integrated processes.
NPK fertilisers are formulations of various salts containing appropriate percentages of
the elements.
86
how is ammonia + nitric acid -> ammonium nitrate carried out in industry
giants vats
high conc
very exothermic
heat released is used to evap water from the mixture to make a very conc ammonium nitrate product.
87
how can ammonium salts be made?
By reacting ammonia with acids, incl. nitric acid
88
how is ammonium nitrate made?
ammonia and nitric acid react together (good fertiliser- nitrogen from two sources)
89
how is ammonia + nitric acid -> ammonium nitrate carried out in industry
giants vats
high conc
very exothermic
heat released is used to evap water from the mixture to make a very conc ammonium nitrate product.
90
how is ammonia + nitric acid -> ammonium nitrate carried out in lab
much smaller scale by titration & cristilisation
low conc
less heat produced
safer
aft. titration, mixture is crystalised which give pure ammonium nitrate crystals.
crytalisation isn't used in industry bcos it's v slow.
