p-dichlorobenzene has higher m.p. And solubility than those of o-and m-isomers. Discuss.

Explanation

The para-isomer, with more symmetrical structure, can be packed more closely in the crystal lattice and thus has stronger intermolecular forces of attraction than those of the ortho-and meta- isomers. Crystal lattice must be broken for melting or dissolution of a compound. Thus, large amount of energy is needed to melt or dissolve p-dichlorobenzene than ortho- & meta-dichlorobenzens. Thus m.p. of para-isomer is greater and its solubility is lower than ortho- and meta- isomers.