Pearson Edexcel International GCSE (9–1) · CHEMISTRY · Chapter
Synthetic Polymers
107 practice questions
Topics covered
Practice questions
31–40 of 46 · Normal
Question 31
4 marks · Normal
Answer and see the solution →The table shows the properties of two polyesters.
Properties of Polyesters A and B Polyester Monomers Used Melting Point / C Tensile Strength A ethane-1,2-diol + benzene-1,4-dicarboxylic acid 258 High B propane-1,3-diol + benzene-1,4-dicarboxylic acid 140 Medium (a)[2 marks]State one similarity and one difference in the monomers used to make Polyesters A and B.
(b)[2 marks]Using the data in the table, suggest a reason for the difference in melting point between Polyester A and Polyester B.
Question 32
1 mark · Normal
Answer and check →Which of the following statements about polyesters is correct?
- A.Polyesters are formed by addition polymerisation of alkenes.
- B.Polyesters are made from diols and dicarboxylic acids by condensation polymerisation.
- C.Only one type of monomer is needed to form a polyester.
- D.No water is lost when making a polyester.
Question 33
2 marks · Normal
Answer and see the solution →Give one everyday use of polyesters and state one property of polyesters that makes them suitable for this use.
Question 34
4 marks · Normal
Answer and see the solution →(a)[2 marks]Write a balanced chemical equation using structural formulae for the reaction between ethane-1,2-diol (HOCH2CH2OH) and butane-1,4-dioic acid (HOOCCH2CH2CH2COOH) to form a polyester and water.
(b)[2 marks]Explain why the product formed is called a polyester.
Question 35
2 marks · Normal
Answer and see the solution →State the two types of functional groups present in lactic acid that allow it to form a biodegradable polyester.
Question 36
4 marks · Normal
Answer and see the solution →Biodegradable polyesters such as PLA can be broken down by environmental processes more easily than many other polymers.
(a)[1 mark]Explain what is meant by the term 'ester linkage' in a polyester.
(b)[3 marks]Describe why polyesters with ester linkages are more biodegradable than addition polymers.
Question 37
3 marks · Normal
Answer and see the solution →Lactic acid has the molecular formula . A single lactic acid molecule is used as the monomer for making polylactic acid (PLA).
Calculate the molecular formula of the repeat unit of PLA, given that one molecule of water () is eliminated each time two lactic acid monomers link. Show your working.
Question 38
4 marks · Normal
Answer and see the solution →The table shows the time taken for different types of polymers to degrade in soil:
Degradation times of polymers in soil Polymer Degradation time (months) PLA (polylactic acid) 12 Poly(ethene) 400 Poly(ester) 18 Poly(propene) 350 Use the data to answer the questions.
(a)[1 mark]Which polymer is the most biodegradable? Give the evidence from the table.
(b)[3 marks]Explain, using your knowledge of chemical structure, why PLA degrades faster than poly(ethene) or poly(propene).
Question 39
1 mark · Normal
Answer and check →Which of the following shows the correct displayed formula for the repeat unit of polylactic acid (PLA)?
- A.—[O—CH(CH3)—CO]—
- B.—[CH2—CH(OH)—CO]—
- C.—[O—CH2—CO]—
- D.—[CH(OH)—CH3—COO]—
Question 40
2 marks · Normal
Answer and see the solution →Describe how polylactic acid (PLA) is produced from its monomer, lactic acid.