Edexcel IAL Chemistry 15.16 Polyester condensation polymerisation

Find the ester link first, then reconstruct the diol and acid fragments or draw continuation bonds so the repeat unit has the correct atoms at each end.

Exam points

Choose repeat units formed from a named diol and dicarboxylic acid pair.
Draw two repeat units with ester linkages and continuation bonds shown.
Deduce the two monomers or single hydroxy-acid monomer from the repeat unit.

[Maximum number: 3]

This question is about carboxylic acids and their derivatives.

An organic compound E contains carbon, hydrogen and oxygen only.

Data from the high resolution proton NMR spectrum of E is shown.

Table for Question 15.20—Both low and high resolution proton NMR spectroscopy to: i predict the different types of proton present in a molecule question 1 — Edexcel A-Level Chemistry A2

Deduce the structure of E.
Justify your answer by labelling the protons responsible for each peak.

structure of E

- 2 or 3 proton environments correct

- $4{ }^{\text {th }}$ proton environment correct

(1)

(1)

(1)

Figure for Answer to Question 15.20—Both low and high resolution proton NMR spectroscopy to: i predict the different types of proton present in a molecule question 1 — Edexcel A-Level Chemistry A2

Example of structure:

Protons can be circled and labelled or just labelled Allow labels using data from the table

Only 1 proton from each group needs to be labelled

Allow whole groups to be labelled, including the carbon atom

(3)

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15.20—Both low and high resolution proton NMR spectroscopy to: i predict the different types of proton present in a molecule question 1