Biology Biomolecules ETEA 2023 Retake
PMDC Verified Question 45 of 142
____ is the heat required to convert a gram of water into vapors at its boiling point.
A
Specific heat capacity
B
Heat of ionization
C
Polarity of water
D
Heat of vaporization
Tap any option to test your recall and reveal the step-by-step Propolis autopsy.

Propolis Cognitive Error Autopsy

Official Correct Choice:
Option D: Heat of vaporization
Concept:

Thermodynamic definitions relating to phase transitions.

Solution:

  • The amount of thermal energy specifically required to completely break the intermolecular hydrogen bonds of 1 gram of a liquid, transitioning it entirely into a gas at a constant temperature (boiling point), is defined strictly as its Heat of vaporization.


  • For water, this value is exceptionally high (574 kcal/kg), powering the massive cooling effect of sweating.


Why other options are incorrect:

  • Specific heat capacity: This is the heat required to merely raise the temperature of 1 gram of a substance by 1°C, without changing its phase.


  • Heat of ionization / Polarity: Unrelated to thermal phase change measurements.

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.

Previous Question All Biomolecules MCQs Next Question

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.

Enter Arena Sprint iOS App Android App