Chemistry Liquids NUMS 2022
PMDC Verified Question 47 of 73
The boiling point of compound is mostly raised by:
A
Dipole-induced dipole interaction
B
London dispersion forces
C
Intra molecular H - bonding
D
Inter molecular H - bonding
Tap any option to test your recall and reveal the step-by-step Propolis autopsy.

Propolis Cognitive Error Autopsy

Official Correct Choice:
Option D: Inter molecular H - bonding
Concept:

Boiling point elevation is heavily dependent on the strength of attractions between separate molecules in a liquid.

Formula:

$$ \text{B.P.} \propto \text{Intermolecular Force Strength} $$

Solution:

  • Intermolecular Hydrogen Bonding creates strong, pervasive electrostatic linkages between multiple separate molecules across the entire liquid volume, requiring massive thermal energy to break apart, raising the boiling point dramatically.


  • Intramolecular H-bonding occurs strictly within a single molecule (e.g., ortho-nitrophenol). Because the molecule is busy bonding with itself, it interacts less strongly with neighboring molecules, generally leading to a lower boiling point.


Why other options are incorrect:

London dispersion and dipole-induced forces are relatively weak compared to genuine Intermolecular Hydrogen bonding.

Quality & Fidelity Assurance: Every question on BeambePrep is rigorously curated against the official PMDC syllabus with zero filler, zero out-of-syllabus content, and zero typos. When an authentic past paper originally contained a historical mistake or ambiguity from the examining board (such as UHS or NUMS), BeambePrep faithfully reflects the original paper while detailing the nuance and scientific consensus in the autopsy above.

Want to solve full-length papers under timed exam conditions?

Practice with zero-scroll lockdown sprints, dynamic latency zone timers, live peer selection telemetry, and the automated Amber mistake recovery loop.