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CAIE A-Level Chemistry AS 18.2 Esters Questions

Practise forming, naming and breaking ester links from structural formulae, reagents, hydrolysis conditions and product tables.

Syllabus
2028–2030
Course
Chemistry 9701
Level
AS

Exam points

  • choose the alcohol and carboxylic acid that form a named or drawn ester
  • identify hydrolysis products under dilute acid or aqueous alkali from an ester structure

Covered syllabus points

18.2.1—Preparation of esters18.2.2—Hydrolysis of esters by dil. acid and by dil.

Question 1

[Maximum number: 2]

4(CH3)3CCHO4\left(\mathrm{CH}_{3}\right)_{3} \mathrm{CCHO} is used in the synthesis of some antibiotics.

Two reaction sequences are shown.

Figure for Question 1 — CAIE A-Level Chemistry AS
Figure for Question 1 — CAIE A-Level Chemistry AS

Draw the structure of the organic molecule T that reacts with A,(CH3)3CCO2H\mathbf{A},\left(\mathrm{CH}_{3}\right)_{3} \mathrm{CCO}_{2} \mathrm{H}, in reaction 2, to form U.

Suggest a catalyst for reaction 2.
T
catalyst

Question 2

[Maximum number: 2]

Allyl chloride is an important chemical used in the manufacture of plastics, pharmaceuticals and pesticides.

allyl chloride

allyl chloride

A series of reactions starting from allyl chloride is shown.

Figure for Question 2 — CAIE A-Level Chemistry AS

The organic product of reaction 3 is Y.
Y can be hydrolysed using excess aqueous H2SO4\mathrm{H}_{2} \mathrm{SO}_{4} to form Z.
The molecular formula of Z is C4H8O4\mathrm{C}_{4} \mathrm{H}_{8} \mathrm{O}_{4}.
Draw the structure of Z.

Question 3

[Maximum number: 3]

Compounds P and Q are structural isomers.

Fig. 4.1

Fig. 4.1

Fig. 4.3 shows a synthesis starting from T, a different isomer of R and S.

Fig. 4.3

Fig. 4.3

V reacts with propan-2-ol in the presence of a catalytic amount of H2SO4\mathrm{H}_{2} \mathrm{SO}_{4} to form organic compound W.

Complete Table 4.1 to give details of this reaction.

Table 4.1

Table 4.1

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