Pearson Edexcel International GCSE (9–1) · CHEMISTRY · Unit
Organic Chemistry
785 practice questions
Topics covered
Practice questions
301–310 of 317 · Easy
Question 301
1 mark · Easy
Answer and see the solution →Draw the structure of the repeat unit of polylactic acid (PLA) formed from lactic acid monomers.
Question 302
3 marks · Easy
Answer and see the solution →Lactic acid, which contains both a carboxylic acid group and an alcohol group in its molecule, can be used to make a biodegradable polyester.
(a)[1 mark]State the two functional groups present in lactic acid that allow it to form a polyester.
(b)[2 marks]Describe how a polyester such as PLA can be formed from lactic acid monomers.
Question 303
1 mark · Easy
Answer and see the solution →State the type of chemical bond in the backbone of PLA that makes it more biodegradable than poly(ethene).
Question 304
3 marks · Easy
Answer and see the solution →Polylactic acid (PLA) is formed by joining multiple lactic acid units.
(a)[1 mark]Draw the displayed formula of lactic acid.
(b)[2 marks]Show (with a labelled diagram or description) how two lactic acid molecules join to form an ester linkage.
Question 305
2 marks · Easy
Answer and see the solution →Polyesters such as polylactic acid (PLA) are more biodegradable than most addition polymers.
Calculate the number of ester linkages in a PLA chain formed from 10 lactic acid monomers. Show your working.
Question 306
2 marks · Easy
Answer and see the solution →Lactic acid () is the monomer for the biodegradable polyester called PLA (polylactic acid).
Draw the displayed (structural) formula for a section of the polylactic acid (PLA) polymer, showing two repeat units joined together.
Question 307
3 marks · Easy
Answer and see the solution →Lactic acid is a monomer that can be used to make the biodegradable polyester polylactic acid (PLA). The data table below shows three monomers, the type of polymerisation they can undergo, and whether the resulting polymer is biodegradable.
Monomer Type of polymerisation Is the polymer biodegradable? Lactic acid Condensation Yes Ethene Addition No Hexanedioic acid and ethane-1,2-diol Condensation Yes Analyse the table and answer the following parts:
(a)[1 mark]State which monomer from the table is used to make PLA.
(b)[1 mark]Based on the table, what type of polymerisation is used to make PLA?
(c)[1 mark]Use the data to give one reason why polylactic acid (PLA) is considered environmentally friendly.
Question 308
5 marks · Easy
Answer and see the solution →Poly(chloroethene) is better known as PVC and is used for making pipes and insulation.
(a)[2 marks]Describe briefly how an addition polymer such as poly(chloroethene) is prepared from its monomer.
(b)[1 mark]Draw the structural formula of the monomer used to make poly(chloroethene).
(c)[2 marks]The displayed formula of a polymer chain is shown below:
Deduce the name and displayed formula of the alkene monomer used to make this polymer.
Question 309
5 marks · Easy
Answer and see the solution →The polymer poly(propene) is produced by the addition polymerisation of propene.
(a)[2 marks]Draw the displayed formula of the repeat unit of poly(propene).
(b)[1 mark]Write the displayed formula of the monomer used to make poly(propene).
(c)[2 marks]How many propene molecules would be needed to form a polymer chain containing 3000 carbon atoms?
Question 310
5 marks · Easy
Answer and see the solution →Poly(chloroethene), also known as PVC, is a common synthetic polymer.
(a)[1 mark]State the name of the monomer used to produce poly(chloroethene).
(b)[2 marks]Describe what occurs to the double bond during addition polymerisation of this monomer.
(c)[2 marks]Deduce and draw the displayed formula of the repeat unit of poly(chloroethene), showing all atoms with their bonds clearly.