JEE Main · 2023 · 31 Jan 2023 · Shift 1 · General Organic Chemistry

The correct order of melting point of dichlorobenzenes is

(A)(see structure)
(B)(see structure)
(C)(see structure)
A
B
(D)(see structure)
✓ Correct

Answer: (D)

Solution

The melting point of a molecular solid depends on how closely its molecules pack in the crystal. Para-dichlorobenzene is the most symmetrical and packs most compactly, so it melts highest, near

5 3^{\circ} C

; ortho-dichlorobenzene melts near

- 1 7^{\circ} C

and meta-dichlorobenzene near

- 2 5^{\circ} C

. The order of melting point is para > ortho > meta.

JEE Main · 2023 · 31 Jan 2023 · Shift 1 · Single correct option

Practise more: all JEE Main PYQs on General Organic Chemistry →

More JEE Main questions on General Organic Chemistry

From the following, the least stable structure is:
JEE Main 2026View solution →
Identify correct statement from the following:

A. Propanal and propanone are functional isomers.
B. Ethoxyethane and methoxypropane are metamers.
C. But-2-ene shows optical isomerism.
D. But-1-ene and but-2-ene are functional isomers.
E. Pentane and 2, 2-dimethyl propane are cha …
JEE Main 2026View solution →
Match List-I with List-II.

List-I (Pair of Compounds):
A. 2-Methylpropene and but-1-ene
B. Cis-but-2-ene and trans-but-2-ene
C. 2-Butanol and diethyl ether
D. But-1-ene and but-2-ene

List-II (Type of Isomers):
I. Stereoisomers
II. Position isomers
III. Chain isomers
IV. Functio …
JEE Main 2026View solution →
Given below are two statements:

Statement-I: Compound (X), shown below, dissolves in $NaHCO_{3}$ solution and has two chiral carbon atoms

Statement-II: Compound (Y), shown below, has two carbons with $sp^{3}$ hybridization, one carbon with $sp^{2}$ an …
JEE Main 2026View solution →
The IUPAC name of the following comopound is :
JEE Main 2026View solution →
Consider all the structural isomers with molecular formula $C X_{5} H X_{11} Br$ are separately treated with KOH (aq) to give respective substitution products, without any rearrangement. The number of products which can exhibit optical isomerism from these is ____ .
JEE Main 2026View solution →