BRAINCAKEPlane-Polarised Light
Ordinary light is made of electromagnetic waves that vibrate in all planes at right angles to the direction the light travels. When light passes through a polarising filter, only the waves vibrating in one plane get through. This is plane-polarised light.
When plane-polarised light passes through a solution of a single optical isomer, the plane of polarisation is rotated. Optical activity is the ability of a single optical isomer to rotate the plane of polarisation of plane-polarised light, and such a substance is described as optically active.
The two enantiomers of a compound rotate the plane by the same angle but in opposite directions: one clockwise and the other anticlockwise. This is the simplest physical way to tell a pair of enantiomers apart.
Sign in free to see the rest of this lesson, the R.E.C.I.P.E. recall steps and the quiz
BrainCake is free. Make an account in seconds and pick up where this page stops.
More in Chirality
- Chirality
- Optical Isomers
- Racemic Mixtures
- Racemates from Nucleophilic Addition
- Identifying Chiral Centres
All 6 lessons in Chirality · All Edexcel A-level Chemistry topics