A meso compound or meso isomer is a non-optically active member of a set of stereoisomers, at least two of which are optically active. This means that despite containing two or more stereogenic centers, the molecule is not chiral.

Can meso be chiral?

Meso compounds are achiral compounds that has multiple chiral centers. It is superimposed on its mirror image and is optically inactive despite its stereocenters.

How do you know if a molecule is chiral or meso?

By definition, a molecule that's not superimposable on its mirror image is a chiral molecule. Compounds that contain chiral centers are generally chiral, whereas molecules that have planes of symmetry are achiral and have structures that are identical to their mirror images. The plane of symmetry in meso compounds.