Chemistry Gases PMDC 2020
PMDC Verified Question 53 of 65
The actual volume of gas molecules is considered negligible at following pressures.
A
2 atm
B
4 atm
C
6 atm
D
8 atm
Tap any option to test your recall and reveal the step-by-step Propolis autopsy.

Propolis Cognitive Error Autopsy

Official Correct Choice:
Option A: 2 atm
Concept:

According to the kinetic molecular theory, ideal gas behavior (where molecular volume is negligible) is best approximated under conditions of low pressure and high temperature.

Solution:

  • At very low pressures, gas molecules are spread far apart, meaning the empty space between them is massive compared to the size of the molecules themselves.


  • As pressure increases, gases are compressed, molecules are forced closer together, and their actual volume becomes significant relative to the total container volume.


  • Among the given options, 2 atm is the lowest pressure. At this state, the gas behaves most ideally, and the actual volume of the molecules is considered negligible compared to the total volume.


Why other options are incorrect:

  • Options B, C, & D: Higher pressures (4, 6, 8 atm) force molecules closer together, increasing non-ideal behavior where the actual volume of the gas molecules can no longer be ignored.

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.

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