Statement 1:
Boiling point order is in decreasing order due to decreasing Vanderwaal's forces. Statement 2:
P-dichlorobenzene has more melting point value due to its symmetric structure than O-dichlorobenzene while it has less boiling point than O-dichlorobenzene.
Statement I is correct but Statement II is incorrect.
Statement I is incorrect but Statement II is correct.
Both Statement I and Statement II are incorrect.
Show Solution
The Correct Option isA
Solution and Explanation
Step 1: Understanding the Question:
The question evaluates factors affecting physical properties (boiling point and melting point) of isomeric organic compounds. Step 2: Detailed Explanation: Regarding Statement 1:
For isomeric alkyl halides, the boiling point decreases as branching increases.
Order: n-butyl iodide > sec-butyl iodide > tert-butyl iodide.
This is because branching decreases the surface area, which in turn decreases the magnitude of Van der Waals forces. Hence, Statement 1 is correct.
Regarding Statement 2:
Melting point depends on crystal lattice packing. p-dichlorobenzene is more symmetrical and fits better in the crystal lattice than o-dichlorobenzene, giving it a higher melting point.
Boiling point depends on dipole-dipole interactions. o-dichlorobenzene has a higher net dipole moment than the para-isomer (where dipoles cancel), leading to stronger intermolecular forces and a higher boiling point for the ortho-isomer. Hence, Statement 2 is correct. Step 3: Final Answer:
Both Statement I and Statement II are correct.
