1
Q
Define polymer
A
A polymer is a very large organic molecule built up from many small units called monomers joined together by covalent bonds through polymerisation
2
Q
state the two types of polymers
A
natural and synthetic (man-made)
3
Q
name 4 natural polymers
A
wool, natural rubber, silk, starch
4
Q
name 4 synthetic polymers
A
-poly(ethene)
-nylon
-terylene
-polyvinyl chloride (PVC)
5
Q
Define addition polymerisation
A
Addition polymerisation occurs when unsaturated monomers joined together covalently without losing any molecules or atoms to form addition polymer
6
Q
structure of monomers used for addition polymerisation
A
usually unsaturated. it contains either a carbon-carbon double bond or carbon-carbon triple bond
7
Q
how to form polymers from alkenes?
A
alkenes undergo addition polymerisation at high temperature and pressure and in the presence of a catalyst to form polymers
8
Q
how do we name polymers
A
poly(monomer)
9
Q
poly(ethene)/polyethylene is what
A
it is the simplest addition polymer produced by the addition polymerisation of ethene monomers
10
Q
how do we form polyethylene/poly(ethene) in full structural formula
A
11
Q
what is the repeat unit
A
the similar units that are joined together to make up of a polymer
12
Q
state t
A
13
Q
which is the monomer, repeat unit and polymer?
A
14
Q
what does the n represent
A
a large number
15
Q
what is the monomer of ethene
A
16
Q
what is the repeat unit to form poly(ethene)
A
17
Q
what is the full structural formula of poly(ethene)
A
18
Q
this polymer can be moulded into various shapes and are used to make cling wraps, plastic bags and plastic toys. what is this polymer?
A
poly(ethene)
19
Q
what is the monomer of tetrafluoroethylene
A
20
Q
what is the repeat unit of tetrafluoroethylene
A
21
Q
what is the polymer of tetrafluoroethylene
A
22
Q
this polymer is heat-resistant and has non-stick properties and is used to coat frying pans. what is this polymer?
A
poly(tetrafluoroethylene)
23
Q
what is the monomer of chloroethene (vinyl chloride)
A
24
Q
what is the repeat unit of chloroethene (vinyl chloride)
A
25
what is the polymer of chloroethene (vinyl chloride)
26
this polymer is waterproof and insulating materials is used to make thin gloves, pipes, raincoats and flooring mats, what is this polymer?
poly(chloroethene) / polyvinyl chloride, PVC
27
what is the polymer of chloroethene (vinyl chloride)
28
what is the monomer of styrene
29
what is the repeat unit of styrene
30
what is the polymer of styrene
31
this polymer is hard, light and brittle and is used to make disposable containers, what is this polymer?
poly(styrene)
32
what is the polymer of styrene
33
Draw the structure of the repeat unit and polymer formed by the monomer shown
34
35
36
define condensation polymerisation
condensation polymerisation occurs when monomers with two reactive functional groups join together covalently to form condensation polymers, with the loss of small molecules such as water
37
name the two main groups of condensation polymers
polyamides
polyesters
38
structure of nylon
nylon is the first synthetic fibre made by condensation polymerisation. it can made from a dicarboxylic acid (molecule with two —COOH groups) and a diamine (molecule with two —NH2 groups)
39
state the full structural formula of the two molecules to make nylon
40
state the full structural formula of nylon
41
state the monomers of nylon
42
state the repeat unit of nylon
43
state the polymer of nylon
44
what is terylene
a synthetic polymer. it is an example of a condensation polymer
45
state the two molecules to make terylene
46
state the full structural formula of terylene
47
state the monomers of terylene
48
state the repeat unit of terylene
49
state the polymer of terylene
50
what are the uses of nylon and terylene
-manufacture of clothing (they do not shrink when exposed to water)
-used as curtain materials (they are shrink-proof and crease-proof, easier to wash and dry)
-manufacture of parachutes, fishing lines and sleeping bags (they are strong and can be drawn into long thin strands without breaking
51
what is the structure of an amide linkage
52
53
54
why are plastics used increasingly in place of natural materials? (4 points)
-relatively cheap
-easily mouded into various shapes
-light, tough and waterproof
-durable (resistant to decay, rusting and chemical attack)
55
Definition of non-biodegradable
They cannot be broken down by bacteria and other living organisms in the soil.
56
what is the biggest problem with the use of plastic
The problem is the disposability of plastics after they are no longer required
57
name 3 environmental problems caused by disposal of non-biodegradable plastics
-land pollution
-water pollution
-air pollution
58
land pollution by plastics (2 points)
-Plastics do not decompose.
-Thus, burying plastic waste in landfills leads to an increasing amount of built-up waste.
59
water pollution by plastics (2 points)
-Plastics thrown into the sea endanger marine animals.
-Plastic may also clog up rivers and drains, which might become breeding grounds for mosquitoes.
60
air pollution by plastics (2 points)
-Plastics are mostly flammable.
-When plastics are incinerated, they produce poisonous gas.
61
2 ways to recycle plastics
using the physical or chemical method
62
why do plastic waste need to undergo pre-treatment
Before recycling is carried out, the plastic waste needs to undergo pre-treatment as not all plastics can be recycled and the recycling method for different types of plastics are different.
63
State 3 pre-treatment of plastic waste
-sorting by different methods (manual sorting, sorting by density)
-washing to remove contaminants
-shredding or grinding to smaller pieces
64
how do physical method of recycling plastics work (3 points)
-Also known as mechanical recycling, this method retains the chemical composition of the recycled plastic.
-After pre-treatment, small pieces of plastics are melted, cooled, pulled into long, thin strands, and cut into pellets.
-These pellets can then be made into new products.
65
how do chemical method of recycling plastics work (3 points)
-The chemical method of recycling plastics converts plastic waste into different raw materials through different chemical reactions
-Plastic waste, such as poly(ethene) waste, can undergo cracking to form short chains of alkanes and alkenes that can be used as fuels and they can be used to make other useful chemicals
66
what does cracking chemical method of recycling plastics require?
high temperature and the presence of a catalyst
67
Define depolymerisation
Depolymerisation is a process in which polymers are broken down into their monomers
68
what happens during acid hydrolysis (polyester depolymerisation)
-this involves breaking down a polyester using water in the presence of an acid catalyst
-the products are the monomers used to form the polyester — a dicarboxylic acid and a diol
69
draw the full structural formula of polyester acid hydrolysis
70
state an example of recycling
recycling polyethylene terephthalate (PET), a polyester that is commonly used to make plastic bottles, that can be recycled using physical and chemical methods
71
stare 3 ways to minimise plastic waste
-reducing use of plastics
-resuing plastics for same or new purpose
-recycling plastic objects instead of throwing it awah
72
when recycling plastics, state the 3 issues
environmental, economic, social issues
73
How does recycling plastics cause environmental issues
Both the physical and chemical methods of recycling plastics may lead to environmental issues.
74
make an example of environmental issue caused by plastics
For example, if wastewater generated from the recycling process is not treated properly before being discharged into water bodies, it can contaminate the water and cause waster pollution.
75
make examples of economic issue caused by plastics (4 points)
-There is cost of transporting the waste to the processing plant, sorting and cleaning the waste and carrying out either physical or chemical recycling processes.
-All the processes require manpower, machines and energy.
-Recycled plastics usually have a lower market value. This means that they are sold at a lower value than virgin plastics.
-It will be difficult for recycling businesses to survive if the cost of recycling plastic waste is too high.
76
How does recycling plastics cause economic issues (2 points)
-Recycling plastics can be expensive, costing more than disposal in landfills or incineration.
-It may not be economically viable to recycle plastics if the cost of recycling plastic waste is higher than the value of the recycled plastics.
77
How does recycling plastics cause social issues (3 points)
-In Singapore, people find it more convenient to throw all their waste away. Hence, recyclable plastics are disposed of and not recycled.
-Many people are not aware of the proper way to recycle plastics. Plastic waste not correctly recycled may not eventually get recycled.
-It takes time and effort for communities to adopt recycling as a lifestyle which might not be immediately effective.
78
make examples of economic issue caused by plastics (2 points)
-If the recyclable items are contaminated with leftover food, they end up being incinerated and not recycled.
-Non-recyclable items, including some types of plastics, are sometimes thrown into recycling bins which increases time and effort to separate recyclables from the waste, slowing down recycling process.
79
How can we address issues related to recycling plastics
Strict measures and laws must be put in place to minimise potential environmental issues. Recycling programs can be introduced to educate the public on the correct way to recycle plastic waste.
Creative activities can be introduced to encourage people to practice recycling.
80
macromolecules definition
Macromolecules are groups of giant covalent structures.
Polymers are macromolecules as a polymer that consists of many covalent molecules joined together into chains of much larger molecules.
81
why do polymers allow them to be made into many different products.
Polymers vary greatly in their
hardness and flexibility because they exist in many different combinations of atoms.
82
Describe the melting and boiling points of polymers (4 points)
-Because of the large size of polymers, most of them are .
at room temperature.
-However, a polymer may be formed by molecules of a range of sizes.
-Thus, polymers do not have a fixed melting or boiling point.
-They typically soften over a range of temperatures when the weaker
intermolecular forces of attraction are overcome by the molecular vibrations with higher kinetic energy.
83
describe this
Poly(ethene) has low melting and boiling points. Low amount of energy is needed to overcome the weak intermolecular forces of attraction between molecules.
84
State other physicql properties of polymers
Most macromolecules are insoluble
in water and soluble in organic solvents. They are not able to conduct electricity in any states as they do not have mobile ions or electrons
85
state 5 differences between addition and condensation polymer
-Addition polymers monomers are unsaturated while condensation polymers have two reactive functional groups
-addition polymers are formed with no loss of atoms or small molecules while condensation polymers are formed with loss of atoms or small molecules
-addition polymers are formed with no change in mass while condensation polymers are formed with change in mass
-addition polymers are formed with same empirical formula as monomers while condensation are formed with different empirical formula as monomers
-addition polymers are formed with only one product while condensation polymers are formed with two products
O LVL Chemistry
flashcards
Decks in class (39)
# Cards
-
O LVL Experimental Chemistry17
-
O LVL The Particulate Nature of Matter14
-
O LVL Chemical Bonding and Structure24
-
O LVL Chemical Calculations16
-
O LVL Acid-Base Chemistry9
-
O LVL Salts22
-
O LVL Ammonia7
-
O LVL Qualitative Analysis53
-
O LVL Oxidation and Reduction14
-
O LVL Patterns in the Periodic Table33
-
O LVL Chemical Energetics4
-
O LVL Rate of Reaction18
-
O LVL Electrochemistry16
-
O LVL Organic Chemistry77
-
O LVL Maintaining Air Quality35
-
Experimental Design42
-
Methods of Purification and Analysis41
-
Kinetic Particle Theory39
-
Metallic Bonding6
-
Atomic Structure22
-
Ionic Bonding8
-
Covalent Bonding4
-
Structure and Properties of Materials36
-
Formulae and Equation Writing25
-
The Mole Concept and Stoichiometry27
-
Acids and Bases47
-
Ammonia26
-
Electrochemistry102
-
Periodic Table71
-
Metal Reactivity Series155
-
Chemical Energetics62
-
Fuels and Crude Oil76
-
Hydrocarbons88
-
Polymers85
-
Colour Chart142
-
Practical161
-
MCQ3
-
Alcohol, Carboxylic Acids and Esters86
-
Titration Errors12
