1. Organic Chemistry Homework 4 - Macromolecules
Name : ……………………………………….. Marks : / 55
Class : ………………………………………... Date :
……………..
Paper 2 [Structured and Free Response Questions]
Section A [Structured Questions]
1 The following terms can be used to describe organic compounds.
alcohol alkene carboxylic acid hydrocarbon
alkane amide ester polymer
From this list, choose two terms which can be applied to each of the following
compounds. The same term may be used more than once.
(a) butene: alkene and hydrocarbon
(b) poly(ethene): polymer and hydrocarbon
(c) nylon: polymer and amide
(d) terylene: polymer and ester
2 A simplified structure of a fat molecule is drawn below.
O H
C O C H
O
C O C H
O
C O C H
H
(a) Fat is a macromolecule found in food. Name two other types of macromolecule
found in food.
1

2. Proteins and carbohydrates
[2]
(b) A fat molecule contains ester linkages.
(i) How many ester linkages does the molecule have?
3 ester linkages
(ii) Draw a ring around one of the ester linkages. [2]
(c) The ester ethyl ethanoate reacts with aqueous sodium hydroxide as
shown below.
H O H H
H C C O C C H + NaOH
H H H
H H H H
H C C ONa + H O C C H
H H H H
A fat molecule reacts with aqueous sodium hydroxide in a similar reaction.
Write the structures of the two products of this reaction.
+
[2]
Section B [Free Response Questions]
1 (a) Kerosene is a mixture of alkanes. The diagram below shows how a mixture of
propene and other hydrocarbons can be produced from kerosene in the laboratory.
2

3. glass wool pieces of broken pot
soaked in kerosene
mixture of gaseous
hydrocarbons
Pyrex boiling small test
tube tube
heat heat
strongly strongly
water
(i) Name the type of reaction shown in the diagram. Cracking
(ii) What is the purpose of the pieces of broken pot?
The broken pot acts as the solid catalyst.
(iii) A typical alkane found in kerosene has the formula C14H30. Construct the
equation for one reaction that takes place in the apparatus producing propene from
C14H30.
C14H30 → C3H6 + C11H24
(b) The structure of propene is shown below.
H H H
H C C C
H H
Propene undergoes polymerisation. The polymer produced is non-biodegradable.
(i) What type of polymerisation takes place?
Addition polymerisation.
(ii) Name the polymer and draw the structure of part of a polymer molecule.
Poly(propene).
3

4. (iii) Explain what is meant by non-biodegradable and give one example of a problem
this can cause.
Non-biodegradable means that the plastic materials cannot be decomposed by
bacteria in soil. Thus, there is a need to find landfill sites to bury waste, causing
land pollution.
[5]
2 (a) The structure of difluorochloroethene is shown below.
F Cl
C C
F H
(i) Difluorochloroethene polymerises to produce a macromolecule. Suggest a
name for the macromolecule and sketch its structure.
Poly(difluorochloroethene).
(ii) When 5 tonnes of difluorochloroethene polymerised, 4.2 tonnes of the
polymer were obtained. Calculate the percentage yield.
Percentage yield = 4.2/5 × 100%
= 84 %
[4]
(b) State one important use of the addition polymer produced from ethene. [1]
Poly(ethene) can be used to make plastic bags/bottles/cling film.
3 Proteins are macromolecules containing the amide link.
(a) Proteins are found in food. Name two other types of macromolecules found
in food. Proteins and carbohydrates.
(b) Sketch the structure of an amide link and name a synthetic type of macromolecule
containing this link.
4

5. Nylon.
(c) Proteins react with water in the presence of a catalyst to produce a mixture of
about 20 different monomers called amino acids. Suggest in outline a method
that could be used to separate and identify the amino acids.
The mixture of amino acids can be separated and identified by paper
chromatography. The separation can be carried out as follows:
(1) Cut a long strip of chromatography paper and draw a starting line with a pencil
about 2 cm from one end of the paper.
(2) Use a capillary tube to place one drop of the mixture on the starting line.
(3) Lower the paper into a tall beaker containing a suitable solvent until the spot of
mixture is just above the surface of the solvent.
(4) Place a lid over the beaker, and leave the it to develop.
(5) Remove the paper when the solvent has almost reached the top of the paper.
(6) Mark the solvent front. Spray the chromatogram with a locating agent.
(7) Allow the paper to dry, and calculate the Rf values of the spots on the
chromatogram. From the Rf values, the amino acids can be identified.
[Give the equation to calculate Rf values and draw a diagram for the set-up of the
experiment]
4 Nylon is a polymer containing an amide bond.
(a) Describe the formation of nylon from its monomers. Use the following terms
in your answer:
monomers polyamide condensation
[Refer to the notes]
[3]
(b) Compare the structures of nylon and protein by
(i) stating one difference between these structures, and
The monomers for making nylon are dicarboxylic acids and diamine, whereas the
monomers for making protein are the amino acids.
(ii) stating one similarity between the structures.
Both nylon and proteins contain amide linkages.
[2]
(c) Nylon is used to make parachutes. State one other use of nylon.
Nylon fibres are used to make ropes, fishing lines, strings for rackets. [1]
5