Topic 8: Polymers and Plastics

Question 1

What is an isotope?

Answer 1

An atoms with the same amount of protons and electrons, however a different number of neutrons.

Question 2

What is a isomer?

Answer 2

An atom with the same molecular formula, different displayed formula. (different saturated formula)

Question 3

What is a hydrocarbon?

Answer 3

A molecule that contains hydrogen and carbon only.

Question 4

What is the homoglegeus seris?

Answer 4

A series of hydrocarbons that have similar chemical properties and a trend in physical properties.

Question 5

What does UNsaturated mean?

Answer 5

That the atom contains a double bond.

Question 6

Propane + oxygen =

Answer 6

carbon dioxide + water

Question 7

C3H8 + 5O2 =

Answer 7

3CO2 + 4H2O

Question 8

What is Cracking?

Answer 8

Cracking can be used to produce smaller and more useful molecules from larger alkanes.

Question 9

What is the general formula for the Alkenes?

Answer 9

CnH2n

Question 10

Fractional distillation of crude oil produces…….

Answer 10

more long chain hydrocarbons than can be used directly and fewer short-chain hydrocarbons than are required.

Question 11

Why do we want to crack larger molecules of fractional distillation?

Answer 11

Because we need the smaller are more useful molecules. Larger molecules are more useless; they have higher boiling points etc.

Question 12

Method for cracking parafin oil to ethene?

Answer 12

1) set up apparatus as shown in diagram (Page 21)
2) gently heat the ceramic catalyst, then heat the decane.
3) collect 2-3 test tubes full of gas (discard the first one)
4) test for the presence of the alkene.

Question 13

How do you test for the presence of an alkene?

Answer 13

Bromine Water Test: addition of Br2 across a double bond. It should go orange/brown to colorless. (Diagram on Page 22).

Question 14

Isomers of Pentene C5H10?

Answer 14

BOOK PAGE 23

Question 15

Making Alkenes: Dehydration?

Answer 15

starting material = alcohol
products = water + alkene
catalyst used Al2O3
(Renewable, ethanol produced by fermentation.)

Question 16

Making Alkenes: Cracking?

Answer 16

starting material = large alkane
products = alkene +smaller alkane
catalyst = aluminium oxide.
Temp = 600-700 degrees.
(non-renewable (alkanes sourced from crude oil)).

Question 17

What are monomers?

Answer 17

Individual building blocks of the polymer.

Question 18

Examples of monomers?

Answer 18

Example 1) Diagram A (page 27) = monomers all the same.

Example 2) Nylon, diagram B (page 27) = different monomers.

Question 19

What are polymers?

Answer 19

Many monomers that are joined together to give a larger chain.

Question 20

Examples of polymers?

Answer 20

Example A) alkenes = addition polymers
The double bond can break to form links to other alkene monomers.
Example B) Carboxylic acids + alcohols = condensation polymers. Formation of each link gives out 1 water molecule.

Question 21

Polymerization of addition polymers (Ethene)?

Answer 21

Page 28: C2H4 + C2H4 + C2H4 = C6H12
Monomer: ethene
Polymer Poly(ethene)

Question 22

Addition polymer Table: Ethene: Repeating unit: Uses?

Answer 22

Ethene: Poly(ethene): Plastic bags

Question 23

Addition polymer Table: Propene: Repeating unit: Uses?

Answer 23

Propene: poly(propene): Bottles & packaging

Question 24

Addition polymer Table: Chloethene: Repeating unit: Uses?

Answer 24

Chloroethene: poly(chloroethene)/polyvinylchloride/PVC: Windows frames & pipes.

Question 25

Addition polymer Table: Phenylethene: Repeating unit: Uses?

Answer 25

Phenylethene: poly(phenylethene)/polystyren: Insulating cups / boxes

Question 26

Addition polymer Table: tertraflurorthene: Repeating unit: Uses?

Answer 26

tertraflurorthene: poly(tertraflurorthene)/Teflon: non-stick cooking equipment.

Question 27

Bromination of Methane: Halogenation?

Answer 27

Is the replacement of one or more hydrogens in an organic compound by halogen atoms.

• When methane is reacted with chlorine, the products of the reaction depend on wether there is an excess of methane or of chlorine.
• If there is an excess of methane it forms chloromethene and hydrogen chloride.

Question 28

Bromination of Methane: Word equation(Excess of methane)?

Answer 28

methane +> chlorine = chlormethane + hydrogen chloride.

Question 29

Bromination of Methane: Word equation(Excess of chlorine)?

Answer 29

methane +> bromine = bromomethane +hydrogen bromide

Question 30

Bromination of Methane: Excess of chlorine?

Answer 30

if there is an excess of chlorine then a mixture of products are formed. Chlorine replaces up to 4 of the hydrogen atoms.

Question 31

Bromination of Methane: Symbol equation (Excess of chlorine)?

Answer 31

CH4(g) + Br2(g) = CH3Br(g) + HBr(g)

Question 32

Bromination of Methane: Structural formula (Excess of chlorine)?

Answer 32

Page 30.

Question 33

Condensation polymers: Nylon: How is it made?

Answer 33

Nylon is made from two different monomers, when they react together a small molecule is eliminated (often water - hence the name condensation polymer). Note that there is a water molecule produced each time a new link is formed. Page 32.

Question 34

Thermoplastics?

Answer 34

Strands are not linked and that plastic is more flexible and it can be melted and remolded.

Question 35

Thermoset?

Answer 35

Strands are cross-linked, plastic is harder and is difficult to remold.

Question 36

Plastic used for water pipes?

Answer 36

Polyviynalchloride.

Question 37

Two changes that occur in the formation of an addition polymer from its monomers?

Answer 37

• many monomers join to make a polymer.

- Double bond is broken to make more single bonds.

Question 38

Reason why addition polymers do not biodegrade easily?

Answer 38

• They have strong forces of attraction between atoms.