Question

Which of the following cannot show a vibrational absorption spectrum?

(a) OCS

(b) H2O

(c) CO2

(d) C H2 = C H2

The question was asked during an online interview.

I'm obligated to ask this question of Vibrational Spectroscopy topic in section Absorption Spectroscopy of Engineering Chemistry I

Answer 1

Correct choice is (d) C H2 = C H2

The explanation is: C H2 = C H2 cannot show vibrational absorption spectrum. OCS, H2O and CO2 can show a vibrational absorption spectrum.