Chemistry Solids UHS 2023
PMDC Verified Question 18 of 54
In anisotropic crystals which property do not change with the change in direction of crystalline structure?
A
Electrical conductance
B
Thermal conductance
C
Molar mass
D
Refractive index
Tap any option to test your recall and reveal the step-by-step Propolis autopsy.

Propolis Cognitive Error Autopsy

Official Correct Choice:
Option C: Molar mass
Concept:
Anisotropy affects physical properties that depend on the internal geometric arrangement of atoms, but it cannot alter intrinsic chemical constants.

Solution:
  • Properties like electrical conductance, thermal conductance, and refractive index all depend on how light, heat, or electrons navigate through the specific arrangement of atoms in the crystal lattice. If the lattice spacing varies by direction, these properties vary (anisotropy).
  • However, Molar mass is an intrinsic, fundamental property of the substance, defined by the atomic weights of the constituent atoms.
  • Molar mass depends solely on the chemical formula, totally independent of crystallographic direction.


Why other options are incorrect:
  • A, B, D: These are classic examples of anisotropic properties that explicitly change depending on the axis of measurement in anisotropic crystals.

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 Solids 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