Ortho, meta & para forms of dihalo benzenes are taken in a single container at −250C. The container is slowly heated up to room temperature and after some time it was found that the container was left with a liquid having some solid residues in it. Solid residue can be:
There are three dichlorobenzene isomers- 1,2-dichlorobenzene (ortho), 1,3-dichlorobenzene (meta), and 1,4-dichlorobenzene (para). 1,2-Dichlorobenzene is a colorless to pale yellow liquid. 1,3- Dichlorobenzeneis a colorless liquid. 1,4-Dichlorobenzene, the most important of the three chemicals, is a colorless to white solid with a strong, pungent odour