Q125 · CSIR NET Chemistry, June 2011
Paper: CSIR NET June 2011 · Subject: Physical Chemistry · Chapter: Molecular Spectroscopy · Topic: Molecular Spectroscopy – General · Marks: 2 · Difficulty: Easy
At room temperature, which molecule has the maximum rotational entropy?
(a)$\mathrm{H}_{2}$
(b)$\mathrm{O}_{2}$
(c)$\mathrm{D}_{2}$
(d)$\mathrm{N}_{2}$
Answer
Answer: B ✓ checked by 4AB · confidence medium
Explanation
S_rot rises with the moment of inertia (all four have σ = 2); O₂ has the largest I (≈1.94×10⁻⁴⁶ kg m²) and hence the largest rotational entropy.
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