Question

the p-isomer is dichlorobenzene has higher melting point than o-and m-isomer why?

Answer 1

Dear Student,
The p-isomer of dichlorobenzene has a symmetrical structure therefore the molecules can closely pack in crystal lattice. The intermolecular forces of attraction are strong and therefore large amount of energy is required to break the bonds. Therefore the p-isomer melts at a higher temperature compared to ortho and meta isomers (having unsymmetrical and less packed crystal structure)
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