Q71 · CSIR NET Chemistry, December 2017
Paper: CSIR NET December 2017 · Subject: Physical Chemistry · Chapter: Molecular Spectroscopy · Topic: Raman · Marks: 2 · Difficulty: Easy
The molecule that will show Raman spectrum, but not IR spectrum, among the following is
(a)$\mathrm{H}_{2}$
(b)HCl
(c)BrCl
(d)$\mathrm{CS}_{2}$
Answer
Answer: A ✓ checked by 4AB · confidence high
Explanation
H₂ has no dipole (IR-inactive) but its polarisability changes on stretching (Raman-active); HCl and BrCl are polar; CS₂ has IR-active asymmetric modes.
Study loop for Molecular Spectroscopy