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CAIE A-Level Chemistry 13.4.5 Identifying Stereoisomerism

Practise locating chiral centres and alkene geometrical isomerism in open-chain, branched and cyclic structures.

Syllabus
2028–2030
Course
Chemistry 9701
Level
AS

Exam points

  • circle each sp3 carbon bonded to four different groups, including groups that differ along a ring path
  • test every C=C carbon for two different substituents before claiming geometrical isomerism
  • use wedge, dash or fixed ring geometry to distinguish the valid spatial arrangements without changing connectivity

13.4.5—Chiral centres and geometrical (cis/trans) question 1

[Maximum number: 1]

Sucrose is a white crystalline solid, C12H22O11\mathrm{C}_{12} \mathrm{H}_{22} \mathrm{O}_{11}. In reaction Z, sucrose reacts with water in the presence of a catalyst, aqueous hydrochloric acid, to form glucose and fructose.

reaction Z

reaction Z

Both fructose and glucose contain chiral centres.

On the diagram of the fructose molecule, label all the chiral centres with an asterisk (*).

Figure for Question 13.4.5—Chiral centres and geometrical (cis/trans) question 1 — CAIE A-Level Chemistry AS
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