If there is no rotation of plane polarised light by a compound in a specific solvent, though to be chiral, it may mean that
(a) the compound is certainly a chiral
(b) the compound is certainly meso
(c) there is no compound in the solvent
(d) the compound may be a racemic mixture
(b) The compounds in which asymmetric carbon atom is present, are called optically active, they rotate the plane of polarised light but the compounds which do not show optical activity in spite of the presence of chiral carbon atoms are called meso-compounds. The absence of optical activity in these compounds is due to the presence of a plane of symmetry in the molecule.