Pearson Edexcel International GCSE (9–1) · CHEMISTRY · Unit
Organic Chemistry
785 practice questions
Topics covered
Practice questions
761–770 of 785
Question 761
5 marks · Easy
Answer and see the solution →Poly(pent-1-ene) is a synthetic addition polymer made from the monomer pent-1-ene.
(a)[2 marks]Draw the displayed formula of the repeat unit of poly(pent-1-ene).
(b)[2 marks]State the name and displayed formula of the monomer used to make poly(pent-1-ene).
(c)[1 mark]Give the type of polymerisation occurring and briefly explain what happens to the double bond in the monomer during the reaction.
Question 762
6 marks · Normal
Answer and see the solution →Addition polymers and condensation polymers such as polyesters are used widely in packaging and fabrics. Answer the following questions about these materials.
(a)[1 mark]State what makes addition polymers, such as poly(ethene), difficult to dispose of in the environment.
(b)[2 marks]Landfill and incineration are two ways of disposing of addition polymers. Give one advantage and one disadvantage of using landfill compared to incineration.
(c)[2 marks]Describe briefly how a polyester is made by condensation polymerisation.
(d)[1 mark]Suggest one advantage in terms of disposal if more consumer products were made using polyesters instead of addition polymers.
Question 763
6 marks · Normal
Answer and see the solution →The use and disposal of polymers is an important topic in chemistry. Answer the following structured questions.
(a)[1 mark]State the two main methods used to dispose of addition polymers.
(b)[2 marks]Explain why addition polymers, such as poly(propene), persist in the environment for a long time.
(c)[2 marks]Complete the word equation for the formation of a polyester by condensation polymerisation:
(d)[1 mark]Suggest one environmental benefit of using condensation polymers, like some polyesters, over addition polymers.
Question 764
6 marks · Normal
Answer and see the solution →A company makes 1200 kg of polyester each day by condensation polymerisation, starting from a diol and a dicarboxylic acid. Poly(ethene), an addition polymer, is also made in the same factory.
(a)[1 mark]During polyester formation, a small molecule is eliminated in the reaction. Name this small molecule.
(b)[3 marks]Calculate the total mass of this eliminated small molecule if 1200 kg of polyester is produced and the elimination forms 19% of the total mass of products. Give your answer to the nearest kg.
(c)[2 marks]Addition polymers do not eliminate any small molecule in their formation. Suggest how this difference affects the disposal of polyesters compared to addition polymers.
Question 765
6 marks · Normal
Answer and see the solution →Read the text and answer the questions that follow.
A city council is deciding whether to promote the use of polyesters in place of traditional addition polymers for packaging. They want to consider both environmental impact and chemical properties.
(a)[2 marks]Explain why many addition polymers are considered non-biodegradable.
(b)[2 marks]Describe the process by which polyesters are formed and how this is different from addition polymerisation.
(c)[2 marks]Suggest and explain one environmental benefit of using some polyesters instead of addition polymers for products that may be discarded into the environment.
Question 766
8 marks · Hard
Answer and see the solution →Polymers can be made using different methods, giving materials with different environmental impacts. Use your knowledge of both addition polymerisation and biodegradable polyesters to answer the following.
(a)[2 marks]Draw the displayed formula for the repeat unit of poly(propene), an addition polymer.
(b)Lactic acid (CH3CH(OH)COOH) can be used to make a biodegradable polyester called PLA (polylactic acid).
(i)[2 marks]Describe how lactic acid monomers join to form PLA. Include the type of reaction and the functional groups involved.
(ii)[2 marks]Draw the displayed formula for the repeat unit of polylactic acid (PLA).
(c)[2 marks]State one advantage of using biodegradable polyesters like PLA instead of addition polymers such as poly(propene) for disposable items.
Question 767
7 marks · Hard
Answer and see the solution →Many artificial polymers have useful properties but create environmental concerns. Answer the following questions about their preparation and degradation.
(a)[2 marks]Describe how addition polymers such as poly(chloroethene) are prepared from their monomers, including the conditions needed.
(b)[2 marks]State and explain one main reason why addition polymers like poly(chloroethene) are not easily biodegradable.
(c)[3 marks]Explain why polyesters such as polylactic acid (PLA) are considered more biodegradable than addition polymers.
Question 768
8 marks · Hard
Answer and see the solution →This question is about the structures of polymers made by different processes.
(a)[2 marks]Draw the displayed formula for the repeat unit of poly(ethene), an addition polymer.
(b)Lactic acid, CH3CH(OH)COOH, can polymerise to form a biodegradable polyester (polylactic acid, PLA).
(i)[2 marks]Draw the structure of a lactic acid monomer, showing all atoms and bonds.
(ii)[2 marks]Draw the displayed formula for the repeat unit of polylactic acid (PLA), as formed from lactic acid.
(c)[2 marks]Explain why PLA is biodegradable, but poly(ethene) is not.
Question 769
7 marks · Easy
Answer and see the solution →Answer all parts about alkanes and alkenes.
(a)[1 mark]State the general formula for alkanes.
(b)[2 marks]Name the hydrocarbon with the formula C4H10 and state if it is an alkane or an alkene.
(c)[2 marks]The hydrocarbon C3H6 can be drawn as a straight chain with a double bond. Write its name and draw its displayed formula.
(d)[2 marks]Explain the main difference between alkanes and alkenes in terms of their bonding.
Question 770
7 marks · Easy
Answer and see the solution →Answer the questions about the structure and naming of unbranched alkanes and the C=C bond in alkenes.
(a)[2 marks]Draw the displayed formula of pentane (an unbranched alkane with five carbons) and give its name.
(b)[2 marks]Draw the structure of ethene and label the double bond.
(c)[2 marks]Explain why ethene is classified as unsaturated.
(d)[1 mark]State the type of bond found only in alkenes but not in alkanes.