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

Vedclass pdf generator app on play store
Vedclass iOS app on app store
(N/A) Alkanes experience intermolecular Van der Waals forces. The stronger the force,the higher the boiling point of the alkane.
As branching increases,the surface area of the molecule decreases,which results in a smaller area of contact between molecules.
Consequently,the Van der Waals forces decrease,which can be overcome at a relatively lower temperature. Hence,the boiling point of an alkane chain decreases with an increase in branching.
For example,consider the isomers of pentane $(C_5H_{12})$:
$1$. $n$-pentane (straight chain): Highest surface area,strongest Van der Waals forces,highest boiling point $(309.1 \ K)$.
$2$. iso-pentane ($2$-methylbutane): One branch,lower surface area,lower boiling point $(301.0 \ K)$.
$3$. neo-pentane ($2$,$2$-dimethylpropane): Two branches,spherical shape,smallest surface area,lowest boiling point $(282.5 \ K)$.
Therefore,the order of boiling point is: $n$-pentane $>$ iso-pentane $>$ neo-pentane.

Explore More

Similar Questions

Which of the following alkanes is synthesized from a single alkyl halide by the Wurtz reaction?

$A$ hydrocarbon $C_{5}H_{10}$ does not react with chlorine in the dark but gives a single monochloro compound $C_{5}H_{9}Cl$ in bright sunlight. Identify the hydrocarbon.

Write the structures of different chain isomers of alkanes corresponding to the molecular formula $C_{6}H_{14}$. Also,write their $IUPAC$ names.

Carbon black,which is used in making printer's ink,is obtained by decomposition of

Which is the correct option for the following reaction?
$ 2 CH_3 CH_2 Br \xrightarrow{2 Na / \text{Dry ether}} ? $

Vedclass Products

For Students

Vedclass Test Series

Mock tests in real JEE/NEET style with performance analysis. 5-day free trial.

Start Free Trial
For Teachers

Exam Paper Generator

Generate Set A/B/C/D exam papers from 7.5L+ questions in 2 minutes. 3 chapters free.

Try Free
For Institutes

Online Exam Module

Live online exams with unlimited students, 360° analytics & white-label branding.

See Demo