Q89 · CSIR NET Chemistry, June 2015
Paper: CSIR NET June 2015 · Subject: Physical Chemistry · Chapter: Molecular Spectroscopy · Topic: Molecular Spectroscopy – General · Marks: 2 · Difficulty: Easy
The symmetric rotor among the following is
(a)$\mathrm{CH}_{4}$
(b)$\mathrm{CH}_{3} \mathrm{Cl}$
(c)$\mathrm{CH}_{2} \mathrm{Cl}_{2}$
(d)$\mathrm{CCl}_{4}$
Answer
Answer: B ✓ checked by 4AB · confidence high
Explanation
CH₃Cl has a C₃ axis with two equal moments of inertia — a (prolate) symmetric top; CH₄ and CCl₄ are spherical, CH₂Cl₂ asymmetric.
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