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UPSC Combined Geo-Scientist

Chemist

  • 3 descriptive papers
  • 200 marks each
  • 3 h per paper

Mains Paper II covers physical chemistry.

UPSC Combined Geo-Scientist, Mains · 2019 · Mains Paper II

Q12(b). Symmetric carbon dioxide stretch

Question

Why is the symmetric stretching vibration of CO₂ IR-inactive but Raman-active?

Answer in brief

Symmetric stretching changes polarisability but produces no changing dipole moment.

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CoversSymmetric carbon dioxide stretchVibrational spectroscopy

All parts of Question 12