Hydrocarbons - Result Question 20
####3. Isomers of hexane, based on their branching, can be divided into three distinct classes as shown in the figure.
(2014 Adv.)
I.
II. $\Upsilon$ and
III. $[\sim]$
The correct order of their boiling point is
(a) I $>$ II $>$ III
(b) III $>$ II $>$ I
(c) II $>$ III $>$ I
(d) III $>$ I $>$ II
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Answer:
Correct Answer: 3. (d)
Solution:
- PLAN This problem is based on boiling point of isomeric alkanes. As we know more the branching in an alkane, lesser will be its surface area and lesser will be the boiling point
On moving left to right (III to I)
- branching increases
- surface area decreases
- boiling point decreases
Hence, correct choice is (b)
