Final answer:
Optical rotation, or optical activity, is a property of chiral compounds where the plane of polarization of light passing through them is rotated. This rotation can be measured using a polarimeter.
Step-by-step explanation:
Optical rotation, also known as optical activity, is a characteristic property of chiral compounds. Chiral compounds are molecules that have a non-superimposable mirror image. When light passes through a solution of a chiral compound, the plane of polarization of the light is rotated. This rotation can be measured using a polarimeter, which is an instrument used to detect and measure the optical rotation of a substance.
For example, if a chiral compound is dextrorotatory (rotates light to the right), its enantiomer will be levorotatory (rotates light to the left) to the same degree.