UPSC Combined Geo-Scientist, Mains · 2016 · Mains Paper II
Q12(a)(ii). Counting normal modes
Question
Determine the number of normal vibrational modes of hydrogen chloride, hydrogen cyanide, ethene and benzene.
Answer in brief
HCl: 1; HCN: 4; ethene: 12; benzene: 30.
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CoversCounting normal modesMolecular vibrations
All parts of Question 12
- 12(a)(i) Energy absorbed by HI3 marks
- 12(a)(ii) Counting normal modes4 marks
- 12(a)(iii) Microwave activity3 marks
- 12(b)(i) Raman-scattering lines5 marks
- 12(b)(ii) Carbon dioxide normal modes5 marks