Subject: Physical Chemistry · Chapter: Statistical Thermodynamics · Topic: Statistical Thermodynamics – General · Exam: CSIR-NET DEC 2011 · Marks: 2 · Difficulty: Medium
If $\theta_{\mathrm{r}}$ denotes the characteristic temperatures of rotation, then the magnitude of $\left[\theta_{r},\left(H_{2}\right) . \theta_{r}\left(D_{2}\right)\right] /\left[\theta_{r}(H D)\right]^{2}$ (assume the bond lengths to be the same for all the molecules) is:
(a)2/3
(b)3/2
(c)8/9
(d)9/8
Answer
Answer (as printed): C
Explanation
Since $\theta_{r} \propto \dfrac{1}{\mu}$ (when the bond length $r$ is the same).