Haloalkanes and HaloareneshardMCQ MULTIPLE

The intrinsic crystal lattice enthalpy strictly dictates the melting point of solid aromatic halogenHaloalkanes and Haloarenes Chemistry Question

Question

The intrinsic crystal lattice enthalpy strictly dictates the melting point of solid aromatic halogen derivatives. When systematically evaluating and comparing the isomeric derivatives of dichlorobenzene, which of the following advanced statements are physically true?

Answer: A,B,C,D

💡 Solution & Explanation

All statements correctly describe the interplay of molecular geometry and intermolecular forces. A) The $180^\circ$ symmetry of the $p$ -isomer allows perfect, dense stacking in a lattice. B) Dense stacking equals high lattice enthalpy, driving up the melting point. C) Once melted, boiling point depends on liquid-phase attractions. The $p$ -isomer has $\mu = 0$, so it relies solely on London dispersion forces, giving it the lowest BP ($170^\circ C$) compared to $o$ - ($181^\circ C$) and $m$ - ($173^\circ C$). D) The $m$ -isomer's $120^\circ$ angle creates the most awkward shape for efficient packing, giving it the lowest MP ($-25^\circ C$) compared to $o$ - ($-17^\circ C$).

💬
Still have doubts about this question?
Send it to our AI chemistry tutor on WhatsApp — gets answered in minutes
Ask on WhatsApp →

Practice 22,000+ questions like this

AI-adaptive practice, video lectures, and full JEE Advanced Chemistry content — all in one place.

JEE Advanced · JEE Mains · NEET · IChO · AP Chemistry