Q91 · CSIR NET Chemistry, June 2015
Paper: CSIR NET June 2015 · Subject: Physical Chemistry · Chapter: Molecular Spectroscopy · Topic: Rotational · Marks: 2 · Difficulty: Medium
The spectroscopic technique, by which the ground state dissociation energies of diatomic molecules can be estimated, is
(a)Microwave spectroscopy
(b)Infrared spectroscopy
(c)UV-visible absorption spectroscopy
(d)X-ray spectroscopy
Answer
Answer: C ✓ checked by 4AB · confidence high
The source book printed B; on checking, C is correct — see the explanation.
Printed B; IR gives only the first few levels, the electronic spectrum reaches the dissociation limit.
Explanation
The vibrational progression of an electronic (UV–visible) band converges to the dissociation limit; Birge–Sponer extrapolation of it gives D₀ of the ground state.
Study loop for Molecular Spectroscopy