Polymerisation: A Level Chemistry questions with answers
Free Polymerisation questions for A Level Chemistry (9701), part of Inorganic & organic. Each question has the answer and the marking points an examiner would look for.
This question is about addition and condensation polymers.
(a)
Draw the repeat unit of poly(chloroethene) and deduce the structure of the monomer of a polymer with repeat unit –CH₂–C(CH₃)(COOCH₃)–.
[3]
(b)
Explain how you would distinguish addition from condensation polymers from their repeat units.
[2]
(c)
A polymer is made from benzene-1,4-dicarboxylic acid, HOOC–C₆H₄–COOH, and benzene-1,4-diamine, H₂N–C₆H₄–NH₂. Draw the repeat unit and explain its high strength.
[4]
(d)
State one disadvantage of disposing of halogenated addition polymers by incineration.
[1]
Show answers and mark scheme
Part
Answer and marking points
Marks
(a)
–CH₂–CHCl–; CH₂=C(CH₃)COOCH₃
–CH₂–CHCl– with continuation bonds B1 monomer CH₂=C(CH₃)COOCH₃ B2
3
(b)
condensation: linkages with heteroatoms (ester/amide) in backbone; addition: all-carbon backbone
condensation polymers have ester or amide linkages (O or N) in the main chain B1 addition polymers have a backbone of carbon atoms only B1
2
(c)
–CO–C₆H₄–CONH–C₆H₄–NH–; rigid aromatic chains align; extensive H bonding between chains
correct repeat unit B2 rigid planar chains pack closely B1 hydrogen bonds between C=O and N–H of neighbouring chains B1
4
(d)
releases HCl / toxic dioxins
produces HCl / toxic chlorinated compounds such as dioxins B1
1
Question 3Structured · 11 marks
Nylon-6,6 is made from hexanedioic acid, HOOC(CH₂)₄COOH, and 1,6-diaminohexane, H₂N(CH₂)₆NH₂.
(a)
Draw the repeat unit of nylon-6,6.
[2]
(b)
Name the type of polymerisation and the small molecule eliminated.
[2]
(c)
The repeat unit has Mr = 226. A sample of the polymer has a mean Mr of 33900. Calculate the mean number of repeat units in each chain.
[1]
(d)
A laboratory preparation uses hexanedioyl dichloride instead of hexanedioic acid. Suggest why, and name the other product.
[2]
(e)
Nylon is hydrolysed by hot aqueous acid. Give the products of acid hydrolysis.
[2]
(f)
Explain why nylon fibres are strong, in terms of intermolecular forces between chains.
[2]
Show answers and mark scheme
Part
Answer and marking points
Marks
(a)
–NH(CH₂)₆NHCO(CH₂)₄CO–
amide link –CONH– shown B1 complete repeat unit –NH(CH₂)₆NHCO(CH₂)₄CO– with continuation bonds B1
2
(b)
condensation; water
condensation polymerisation B1 water B1
2
(c)
150
33900 ÷ 226 = 150 B1
1
(d)
acyl chloride more reactive, room temperature; HCl
acyl chlorides are much more reactive / react at room temperature B1 hydrogen chloride B1
2
(e)
hexanedioic acid; 1,6-diaminohexane as ammonium salt
hexanedioic acid B1 the diamine as its salt, ⁺H₃N(CH₂)₆NH₃⁺ (allow 1,6-diaminohexane) B1
2
(f)
hydrogen bonds between N–H and C=O of neighbouring chains
hydrogen bonds form between N–H and C=O groups B1 on neighbouring chains, holding chains together B1
2
Question 4Structured · 4 marks
Condensation polymers include polyesters and polyamides.
(a)
Draw the repeat unit of the polyester formed from ethane-1,2-diol and benzene-1,4-dicarboxylic acid.
[2]
(b)
Explain why polyesters are biodegradable but poly(ethene) is not.
[2]
Show answers and mark scheme
Part
Answer and marking points
Marks
(a)
–OCH₂CH₂OOC–C₆H₄–CO–
correct ester linkages B1 correct repeat unit B1
2
(b)
ester links hydrolysed
ester linkages can be hydrolysed (by enzymes/acid) B1 poly(ethene) has only non-polar C–C/C–H bonds B1
2
Question 5Structured · 12 marks
This question is about proteins and polyamides.
(a)
Describe the primary, secondary and tertiary structure of a protein.
[4]
(b)
Explain why heating a protein changes its shape but not its primary structure.
[2]
(c)
Compare the structure of a protein with that of nylon-6,6.
[2]
(d)
Explain why poly(lactic acid) is described as biodegradable and why this is an advantage.
[2]
(e)
Draw the repeat unit of the polymer formed from 2-hydroxypropanoic acid, CH₃CH(OH)COOH, and name the type of polymerisation.
[2]
Show answers and mark scheme
Part
Answer and marking points
Marks
(a)
sequence of amino acids; H bonding α-helix / β-sheet; folding by R-group interactions
primary: sequence of amino acids joined by peptide bonds B1 secondary: α-helix or β-pleated sheet held by hydrogen bonds between C=O and N–H B1 tertiary: overall folding held by R-group interactions B1 e.g. disulfide bridges, ionic bonds, hydrogen bonds, van der Waals B1
heat breaks the weaker hydrogen bonds and ionic interactions B1 the covalent peptide bonds (primary structure) are not broken B1
2
(c)
both polyamides with amide linkages; protein from many different amino acids, nylon from two monomers
both contain amide (–CONH–) linkages B1 proteins are made from many different amino acids, nylon from two monomers (diamine and diacid) B1
2
(d)
ester links hydrolysed by microorganisms; less persistent waste
its ester linkages are hydrolysed by water / microorganisms B1 it does not persist in landfill or oceans B1
2
(e)
–O–CH(CH₃)–CO–; condensation
correct repeat unit with ester linkage B1 condensation polymerisation B1
2
Question 6Structured · 12 marks
This question is about condensation polymers.
(a)
Explain what is meant by condensation polymerisation.
[2]
(b)
A polyester is made from benzene-1,4-dicarboxylic acid and ethane-1,2-diol. Draw the repeat unit.
[3]
(c)
A polyamide is made from a dicarboxylic acid dichloride and a diamine. State the advantage of using the acyl chloride instead of the acid, and name the small molecule eliminated.
[2]
(d)
Explain why polyamides such as Kevlar are very strong.
[3]
(e)
Explain why polyesters and polyamides are biodegradable but poly(alkenes) are not.
[2]
Show answers and mark scheme
Part
Answer and marking points
Marks
(a)
monomers join with loss of small molecule such as water or HCl
monomers join together B1 with elimination of a small molecule such as H₂O or HCl B1
2
(b)
–OC–C₆H₄–CO–O–CH₂CH₂–O–
ester linkage correct B1 both monomer residues correct B1 continuation bonds / repeat unit brackets B1
3
(c)
more reactive, reacts at room temperature; HCl
acyl chlorides are more reactive (no heating / faster) B1 HCl is eliminated B1
2
(d)
strong hydrogen bonds between chains; rigid aromatic rings; chains aligned
extensive hydrogen bonding between N–H and C=O of adjacent chains B1 rigid planar benzene rings allow chains to align closely B2
3
(e)
ester/amide linkages can be hydrolysed; C–C backbone non-polar, unreactive
polyesters and polyamides contain polar ester / amide linkages that can be hydrolysed (by enzymes or acids) B1 poly(alkenes) have only non-polar C–C and C–H bonds B1
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Original Cambridge-style practice questions written for mentorriyaz.in. These are not Cambridge past paper questions, and this site is not affiliated with or endorsed by Cambridge University Press & Assessment. Updated 2026-11-04. Paper generator · mentorriyaz.in