JEE Main · 2005 · 08 May 2005 · Offline · Hydrocarbons

Of the five isomeric hexanes, the isomer which can give two monochlorinated compounds is

(A)n-hexane
(B)2, 3-dimethylbutane✓ Correct
(C)2,2-dimethylbutane
(D)2-methylpentane

Answer: (B)

Solution

The isomer that yields only two monochloro products must have just two kinds of hydrogen. 2,3-Dimethylbutane is highly symmetric: every hydrogen is either one of the twelve equivalent methyl hydrogens or one of the two equivalent methine (

C - H

) hydrogens, giving exactly two distinct types. Chlorinating it can therefore substitute in only two places, producing two monochlorinated compounds, whereas the other hexanes have three or four types of hydrogen and give more.

JEE Main · 2005 · 08 May 2005 · Offline · Single correct option

Practise more: all JEE Main PYQs on Hydrocarbons →

More JEE Main questions on Hydrocarbons

Identify A in the following reaction.
JEE Main 2026View solution →
Given below are two statements :

Statement I : Benzene is nitrated to give nitrobenzene, which on further treatment with
$CH_{3} COCl / AlCl_{3}$ will give
JEE Main 2026View solution →
As compared with chlorocyclohexane, which of the following statements correctly apply to chlorobenzene?
A. The magnitude of negative charge is more on chlorine atoms
B. The $C - Cl$ bond has partial double bond character
C. $C - Cl$ bond is les …
JEE Main 2026View solution →
The cycloalkane ( X ) on bromination consumes one mole of bromine per mole of ( X ) and gives the product ( Y ) in which $C : Br$ ratio is $3 : 1$ . The percentage of bromine in the product $(Y)$ is
____ %. (Nearest integer)
(Given : Molar mass …
JEE Main 2026View solution →
The dibromo compound [P] (molecular formula: $C_{9} H_{10} Br_{2}$ ) when heated with excess sodamide followed by treatment with dilute HCl gives [Q]. On warming [Q] with mercuric sulphate and dilute sulphuric acid yield [R] which gives positive Iodoform t …
JEE Main 2026View solution →
But-2-yne and hydrogen (one mole each) are separately treated with (i) $Pd / C$ and (ii) $Na /$ liq. $NH_{3}$ to give the products X and Y respectively.

Identify the incorrect statements.
A. $X$ and $Y$ are stereoisomers.
B. Dipole moment of X …
JEE Main 2026View solution →