A racemic mixture, or racemate, is a solution in which both enantiomers of a substance are present in equal proportions. A (d/l)- or ()- prefix in front of the substance's name can be used to represent racemic mixes. A racemic combination has no optical activity since enantiomers have equal and opposing specific rotations. As a result, polarimetry alone cannot distinguish a racemic combination from an achiral material. It's important to note that the phrases chiral and optically active are not interchangeable. To argue that a racemic combination is achiral is erroneous. Individual molecules have chirality as a property. An attribute of solutions is optical activity. Although chiral molecules make up a racemic combination, it has no net optical activity.