Answer
See explanation
Work Step by Step
ortho means (1,2) position of the benzene ring.
meta means (1,3) position of the benzene ring.
para means (1,4) position of the benzene ring.
a) ortho, meta and para isomers of dichlorobenzene are written below. The name of those compounds are: o-dichlorobenzene, m-dichlorobenzene, and p-dichlorobenzene.
b) three (03) isomers are possible for trichlorobenzene which are 1,2,3-trichlorobenzene; 1,2,4-trichlorobenzene and 1,3,5-trichlorobenzene. Structure of each compound is written below.
c) As chlorine atom is ortho-para orienting group i.e. the second substituent will be added to ortho or para position when there is already a chlorine atom is present in the benzene ring. So, m-dichlorobenzene cannot be synthesized directly in one step from chlorobenzene.
d) of the three isomers of trichlorobenzene, 1,2,3-trichlorobenzene will be the hardest to prepare due to steric hindrance among three Cl atoms.
