A racemic mixture is represented by prefixing dl or (±) before the name, such as (±) butan-2-ol. It signifies a mixture containing equal proportions of enantiomers, resulting in zero optical rotation due to cancellation of rotations from each isomer.

Stereoisomers that are non-superimposable mirror images of each other are called enantiomers, which possess identical physical properties but differ in the rotation of plane-polarized light.

Butan-2-ol is a chiral molecule because it has four different groups attached to the tetrahedral carbon, resulting in non-superimposability on its mirror image.

The presence of a single asymmetric carbon, or stereocentre, in a molecule is an aid in recognizing chirality. Molecules with this feature are often chiral, leading to non-superimposability of their mirror images and optical activity.

Chirality in molecules refers to the property of being non-superimposable on their mirror images. Chiral molecules exhibit optical activity, while achiral molecules are optically inactive.