BRAINCAKEIdentifying Chiral Centres
To decide whether a molecule is chiral, look for a chiral centre: a carbon atom with four different groups attached. A chiral centre is usually marked with an asterisk (*) on the structure.
A quick method:
1. Draw the displayed or skeletal formula so you can see every group.
2. Rule out carbons that cannot be chiral centres:
• any carbon in a C=C or C=O double bond, because it has only three groups attached
• CH3 and CH2 carbons, because they have two or more identical hydrogen atoms
3. For each remaining carbon, list the four groups attached. Look at the whole group, not just the first atom: CH3 and CH2CH3 both start with carbon, but they are different groups.
Sign in free to see the rest of this lesson, the R.E.C.I.P.E. recall steps and the quiz
BrainCake is free. Make an account in seconds and pick up where this page stops.
More in Chirality
All 6 lessons in Chirality · All Edexcel A-level Chemistry topics