10. Using Resources Flashcards
1
Q
What are finite resources?
A
Those that are being used up at a faster rate than they can be replaced
2
Q
Examples of finite resources?
A
- oil
- coal
- gas
- gold
- helium
3
Q
What are renewable resources?
A
Those that can be replaced at the same rate at which they are used up
4
Q
Examples of renewable resources?
A
- biofuel
- tidal energy
- wind energy
- wood
- geothermal
- hydroelectric
- cotton
5
Q
What is sustainability?
A
Developments that meet the needs of today’s society, without endangering the ability of the future generations to meet their needs
6
Q
How long does wood take to form?
A
10 years
7
Q
How long does cotton take to form?
A
120-180 days
8
Q
How long does coal take to form?
A
10 to the power of 6 years
9
Q
What is wool used for?
A
Clothes, carpets
10
Q
What is cotton used for?
A
Clothes, textiles
11
Q
What is silk used for?
A
Clothes
12
Q
What is linseed oil used for?
A
Paint
13
Q
What is rubber used for?
A
Tyres
14
Q
What is wood used for?
A
Construction
15
Q
What is an alternative synthetic product to wool?
A
Acrylic fibre (polypropene)
16
Q
What is an alternative synthetic product to cotton?
A
Polyester
17
Q
What is an alternative synthetic product to silk?
A
Nylon
18
Q
What is an alternative synthetic product to linseed oil?
A
Acrylic resin
19
Q
What is an alternative synthetic product to rubber?
A
Various synthetic polymers e.g. polybutadiene
20
Q
What is an alternative synthetic product to wood?
A
PVC composites (MDF)
21
Q
Where do dissolved substances in rainwater come from?
A
As water reaches land it will dissolve substances it comes into contact with such as microorganisms from rocks and soil
22
Q
How does rainwater become acidic?
A
The rainwater will dissolve gases from the atmosphere such as CO2 and nitrogen dioxide which will make it acidic
23
Q
What is potable water?
A
Water that is safe enough to drink without it causing any health problems
24
Q
How is rainwater made potable?
A
- water passed through filter made of sand and gravel - remove insoluble particles e.g. mud
- passed through screen of crossed metal bars to stop large objects e.g. twigs
- left in settlement tank where sand and grit sink
- aluminium sulphate added - smaller particles clump together and sink
- larger particles removed
- sterilise - microorganisms are removed using chlorine and ozone
- pH corrected to neutral
25
What is used to sterilise rainwater?
Chlorine and ozone
26
How is sea water made potable?
Desalination
27
What are the methods of desalination?
Distillation and reverse osmosis
28
How is water desalinated using distillation?
* water is heated and evaporates, leaving dissolved salts behind
* water then cooled, condensed and collected
29
Advantages of using distillation to desalinate sea water?
In hot countries solar power can heat the water
30
Disadvantages of using distillation to desalinate sea water?
High energy costs to heat water
31
How is water desalinated using reverse osmosis?
* water placed under pressure to overcome natural osmotic pressure
* water passes through semipermeable membrane, leaving the solute behind
32
Advantages of using reverse osmosis to desalinate sea water?
No heating required
33
Disadvantages of using reverse osmosis to desalinate sea water?
Energy needed to apply pressure
Salt water corrodes the pumps
34
What are the sources of sewage?
* toilets
* bath/shower water
* washing machines
* dishwashers
* agriculture e.g. hydroponics
35
Where does sewage water go?
To sewage treatment plants to make it safe before it can be returned to the environment, usually into rivers or the sea
36
What is the process of treating sewage water?
* screened to remove large bits (twigs) and grit
* sedimentation - heavier solids sink to the bottom to produce sediment
* effluent floats on top
* effluent removed and treated by aerobic digestion
* sediment broken down by anaerobic digestion - producing methane which can be used as an energy source
37
What is effluent?
Liquid waste
38
What is aerobic digestion?
Where bacteria break down any organic matter
39
What is anaerobic digestion?
A series of biological processes in which microorganisms break down biodegradable material in the absence of oxygen
40
What does anaerobic digestion produce?
Methane gas which can be used as an energy source
41
Advantages of treating sewage over desalination?
* use methane for energy
* use fertiliser afterwards
* use less energy
42
Disadvantages of treating sewage over desalination?
People don't like the idea of drinking water that used to be sewage
43
What is a metal ore?
Ores are naturally occurring rocks that contain enough metal or metal compounds to make it economical to extract them
44
What metals are said to be found native?
The least reactive ones e.g. silver, gold, platinum
45
What is malachite?
A copper ore containing copper carbonate
46
How is copper oxide produced from copper ore?
Thermal decomposition (smelting)
47
What is smelting?
Thermal decomposition
48
What is phytomining?
When plants absorb copper compounds through their roots and concentrate these compounds as a result. Plants can be burned to produce an ash that contains the copper compounds
49
Advantages of phytomining?
* low cost
* plants can be easily monitored
* possibility of recovery and reuse of valuable metals
* potentially least harmful method because it uses natural occurring organisms
50
Disadvantages of phytomining?
* limited to the surface area and depth occupied by the roots
* slow growth and low biomass require a long term commitment
* survival of plants is affected by toxicity of contaminated land and condition of soil
* contaminants into the plants can be passed on in food chain - so requires safe disposal
51
What is bioleaching?
The process of using bacteria to dissolve metals instead of chemical solutions
52
Advantages of bioleaching?
* simpler and cheaper to operate and maintain
* more environmentally friendly
* less landscape damage occurs
* bacteria can be cultivated and recycled
* can be to used extract from ores that are too poor for other technologies
53
Disadvantages of bioleaching?
* bacterial leaching process is slow - bringing in less profit
* toxic chemicals are sometimes produced
* sulphuric acids and H+ ions that have been formed can sometimes leak into the ground turning it acidic
54
What are some copper alloys?
Bronze and brass
55
What is bronze made of?
Copper and tin
56
What is brass made of?
Copper and zinc
57
What is bronze used for?
* statues and decorative items
| * ships, propellers
58
Properties of bronze?
Strong, resistant to corrosion
59
What is brass used for?
Hammered into intricate shapes, used to make musical instruments
60
Properties of brass?
Harder than copper, still workable
61
What are gold alloys used for?
Jewellery
62
What is gold usually alloyed with?
Copper
63
How do you find purity?
Divide carat number by 24 then multiply by 100
64
Properties of aluminium alloys?
Low density, light weight but strong
65
What are aluminium alloys used for?
* making aircraft
| * armour playing for military vehicles
66
What are steels?
Alloys of carbon that contain carbon and other metals
67
Properties of high carbon steel?
Strong but brittle
68
Properties of low carbon steel?
Softer and more easily shaped
69
Which steels are hard and resistant to corrosion?
Steels with chromium and nickel (stainless steels)
70
What happens to molecules during polymerisation?
* double bond between two carbon atoms is broken
* another ethene monomer bonds to the first (addition polymerisation)
* polymer chain grows and more ethene monomers bond
* branching occurs at high temperatures and pressures
* polyethene is formed
71
What is the formula of polyethene?
CnH2n
72
When does branching occur?
At high temperature and pressures, and if a catalyst is not used
73
Properties of high density poly(ethene)?
* fewer branches
* strong intermolecular forces
* strong polymers, more rigid
74
What is high density poly(ethene) used for?
Plastic bottles, bottle caps, water pipes
75
Properties of low density poly(ethene)?
* more branched chains
* weaker intermolecular forces
* weaker, more flexible
76
What is low density poly(ethene) used for?
Plastic bags, plastic wraps, cable insulation
77
Which type of polymers can pack closely together?
Those with few or no branches such as polyethene. The chains are attracted to each other by intermolecular forces
78
What type of plastics melt when heated?
Thermosoftening
79
Properties of thermosoftening plastics?
* melt when heated
* no crosslinks between chains
* held together by only intermolecular forces
* low melting points
* more flexible
80
Examples of thermosoftening plastics?
Poly(ethene), poly(propene) and poly(vinyl chloride)
81
Properties of thermosetting plastics?
* do not melt when heated
* held together by strong covalent cross link bonding
* high boiling points
* more rigid
82
Examples of thermosetting plastics?
Vulcanised rubber and Bakerlite
83
What is corrosion?
The destruction of materials by chemical reactions with substances in the environment
84
Example of corrosion?
Rusting
85
What are necessary for iron to rust?
Oxygen and water
86
What is sacrificial protection?
Iron could be coated with a more reactive metal. The zinc will corrode first, preserving the iron
87
What happens to iron structures that are too large to be galvanised?
Blocks of more reactive metal can be attached to the iron structure. They must be replaced before it all dissolves
88
What happens when aluminium is being corroded?
* aluminium is reactive and will quickly be oxidised
| * aluminium oxide layer forms quickly and is not crumbly like iron oxide - acts like a protective coating
89
Ways to prevent corrosion?
* painting/covering in plastic or oil
* sacrificial protection
* galvanising
* attaching a more reactive metal
90
What is taken into account when considering the life cycle of a product?
* extracting and processing raw materials
* manufacturing and processing
* use and operation during its lifetime
* disposal at the end of its useful life
91
How is a life cycle assessment carried out?
* listing energy and material inputs and outputs to the environment
* evaluating potential environmental impacts from inputs and outputs
* interpreting results to make decisions about material, process, service
92
How is LCA data presented?
Collected into a single score (1-10) - requires subjective judgement - bias from people who paid for study
93
What does the term reduce mean?
Lessening the use of limited resources to make materials
94
What does the term reuse mean?
Reusing products to reduce the production of new materials from limited resources
95
What does the term recycle mean?
The process of converting waste materials into new materials and objects
96
How are glass bottles recycled?
They are crushed and melted to make different glass products
97
How are metals recycled?
By melting and recasting ore reforming into different products
98
Examples of metals that can be recycled?
* aluminium
* steel
* copper
* silver
* gold
99
What is the difference between sacrificial protection and galvanising?
* galvanising means coating with a more reactive metal which is more corrosion-resistant i.e. it's covered in a metal that doesn't corrode
* sacrificial protection is when the reactive metal on top with oxidise instead of the metal underneath
100
Is the Haber process reversible?
Yes
101
What is the word equation for the Haber process?
Nitrogen + Hydrogen <> Ammonia
102
What is the symbol equation for the Haber process?
N2 + 3H2 <> 2NH3
103
Uses of ammonia?
* make fertilisers
* make explosives
* as a cleaning agent in aqueous solution
104
What type of bonding occurs between molecules in ammonia?
Covalent
105
Where does the nitrogen for the Haber process come from?
Air
106
Where does the hydrogen for the Haber process come from?
Methane + steam
107
What does the Haber process do?
Creates ammonia from nitrogen and hydrogen
108
What are the conditions for the Haber process?
* temperature - 450*C
* pressure 200 atm
* iron catalyst
109
What catalyst is used in the Haber process?
Iron catalyst
110
What effect do medium temperatures have on equilibrium yield in the Haber process?
Temperature is decreased for an exothermic reaction so equilibrium shifts to the right in order to raise temperature and make more products
111
What effect do medium temperatures have on rate in the Haber process?
Low temperatures would be cost effective but can't conduct high rates of reaction - so slightly higher temperature is a compromise
112
What effect do medium pressures have on equilibrium yield in the Haber process?
When pressure increases equilibrium shifts to the right so more products are formed
113
What effect do medium pressures have on rate in the Haber process?
Higher pressures are more productive but not practical - expensive
114
What effect does an iron catalyst have on equilibrium yield in the Haber process?
Won't affect equilibrium
115
What effect does an iron catalyst have on rate in the Haber process?
Increase rates of forwards and backwards reactions - reach equilibrium more quickly
116
Why must minerals be soluble for plants?
So they can dissolve in water and plants can absorb them through their roots
117
What are the minerals included in NPK fertilisers?
* nitrogen
* phosphorus
* potassium
118
What are the ions needed by plants?
* nitrates - NO3-
* phosphates - PO3-
* potassium - K+
119
How are fertilisers made?
* prepared in the lab
* reaction of an acid with a base in a neutralisation reaction
* salt solution evaporated until crystals form and these are filtered and dried
120
What is the base in the neutralisation reaction when making synthetic fertilisers?
Ammonia
121
Word equation for ammonium nitrate?
Ammonia + Nitric Acid -> Ammonium Nitrate
122
Word equation for ammonium sulfate?
Ammonia + Sulfuric Acid -> Ammonium Sulfate
123
Word equation for potassium nitrate?
Potassium + Nitric Acid -> Potassium Nitrate
124
What are the sources of phosphate and potassium for fertilisers?
Potassium chloride + sulfide and phosphate rock are obtained by mining, but phosphate rock cannot be used directly as a fertiliser
125
How is phosphate rock treated?
With nitric/sulfuric acid to produce soluble salts that can be used as fertilisers
126
How does the production of fertilisers between the laboratory and in industry differ?
* lab is small scale; industry large scale
* lab - product made in batches; industry produces continuous flow
* lab - ammonia titrated with acid; industry - ammonia gas added to concentrated acid
* lab - dilute reactants; industry - concentrated reacntants
* lab - crystallisation; industry - heat from exo reaction used to evaporate water from mixture and give concentrated product
127
What are the sources of most of the salts in NPK fertilisers?
* mining
| * manufactured by reacting acids with bases
