9701 MCQ Solution 21

Question 21: [Organic > Introductory Organic]:

Camphor is used for medical purposes the diagram shows its structure.

How many chiral centres are present in one molecule of camphor?

A 0

B 1

C 2

D 3

Reference: Past Exam Paper – November 2002 Paper 1 Q21

Solution 21:

Answer: C.

The carbon atom in the top-centre of the molecule is chiral due to asymmetry of the left and right sides. The bottom-centre carbon of the molecule is chiral due to the same reason. The exact centre carbon has 2 methyl groups attached to it thus is not chiral. The rest of the carbon atoms either have multiple hydrogen atoms bonded to it or a double bonded oxygen atom. Hence 2 chiral carbons.