A2 - Optical Isomerism

This is a beautifully simple topic. The final type of isomerism is optical. If a molecule has a carbon atom that has 4 different groups, it is chiral. They can be shown of mirror images. In nature, only one enantiomer is formed. You need to be able to spot these chiral carbons.

If we have a 50:50 mixture of enantiomers, it is called a racemate or a racemic mixture. We can find this by shining plane polarised light through a sample. If the plane of the light is unaltered, then it is a racemic mixture, if the light is rotated, it is either richer in one or completely made up from one enantiomer.