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Karnataka Board PUCPUC Science Class 11

What effect does branching of an alkane chain has on its boiling point?

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Question

What effect does branching of an alkane chain has on its boiling point?

Answer in Brief
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Solution

Alkanes experience inter-molecular Van der Waals forces. The stronger the force, the greater will be the boiling point of the alkane.

As branching increases, the surface area of the molecule decreases which results in a small area of contact. As a result, the Van der Waals force also decreases which can be overcome at a relatively lower temperature. Hence, the boiling point of an alkane chain decreases with an increase in branching.

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Chapter 13: Hydrocarbons - EXERCISES [Page 405]

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NCERT Chemistry - Part 1 and 2 [English] Class 11
Chapter 13 Hydrocarbons
EXERCISES | Q 13.15 | Page 405

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