Racemic Mixture
An equimolar mixture of two enantiomers, which shows no net optical rotation.
Formula / equation
50:50 (+) and (−)
Unit
degrees
In depth
The rotations of the two components cancel exactly, so the mixture is optically inactive despite consisting entirely of chiral molecules. Any synthesis from achiral starting materials gives a racemate, which is why enantioselective synthesis and resolution are so important in pharmaceuticals.
Examples in the real world
SN1 substitution producing a racemate through a planar carbocation; racemic ibuprofen sold as a mixture.