Predicting the Type of Polymerisation (Cambridge (CIE) A Level Chemistry): Exam Questions

Exam code: 9701

14 mins3 questions
1a
1 mark

Glyolic acid is the simplest and only aliphatic monomer needed to form the polymer polyglyolic acid, PGA. The structure of glyolic acid is shown in Fig. 1.1.

glyolic-acid

Fig. 1.1

Give the systematic name of glyolic acid.

1b
1 mark

State of the type of polymerisation involved in the formation of PGA and identify the functional group that forms between the monomers.

type of polymerisation .......................................................................................................

functional group .................................................................................................................

1c
2 marks

Draw a short length of the PGA polymer chain, including a minimum of two monomer residues, with all bonds fully displayed.

Label one repeat unit of polyglyolic acid on your diagram.

1d
1 mark

Predict whether PGA is biodegradable. Explain your answer.

2a
1 mark

The structure of dehydroalanine, shown in Fig. 2.1, makes it an unusual amino acid.

CPFsSSXJ_dehydroalanine-sketch

Fig. 2.1

Name the functional group, in dehydroalanine, that is not common to other amino acids.

2b
1 mark

Draw one repeat unit of the addition polymer formed by dehydroalanine.

2c
2 marks

Dehydroalanine does not easily form a condensation polymer because of the alkene functional group.

The addition of hydrogen to dehydroalanine produces alanine, CH3CH(NH2)COOH. Alanine is easily able to form a condensation polymer.

Draw two repeat units of the condensation polymer formed by alanine. The new functional group formed should be displayed. 

3a
2 marks

Glycine and serine are amino acids with the systematic names 2-aminoethanoic acid and 2-amino-3-hydroxypropanoic acid respectively.

Draw the structures of glycine and serine.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

3b
1 mark

Serine exists as a pair of optical isomers. The structure of one optical isomer is shown in Fig. 3.2.

dNqrOO-Q_serine-optical-isomer-1

Fig. 3.2

Draw the three-dimensional structure of the other optical isomer of serine.

3c
2 marks

Glycine and serine can react to form condensation polymers that contain ester and amide functional groups.

Identify the correct pairings that will separately form an ester and amide.