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IR Spectroscopy Questions and Correct
Answers
4000-2500 Wavenumbers Ans: X-H Single Bonds
2500-2000 Wavenumbers Ans: Tertiary Bonds, C triple C, C triple
N.
2000-1500 Wavenumbers Ans: C=O and C=C.
1500-500 Ans: X-Y single bonds. Other vibrational modes.
How would you produce an IR spectrum for a homonuclear
diatomic? Why would you need to do this instead of regular IR?
Ans: Use Raman spectroscopy. This is because homonuclear
diatomics have no dipole and so do not absorb IR radiation.
C=C Ans: 1635-1690
Benzene Ans: 1450-1625
NO2 Ans: Symmetric - 1350. Anti-symmetric - 1530.
Ketone Ans: 1715
C triple N Ans: 2250
C triple C Ans: 2100-2250
C-H Ans: 2900-3200
© 2025 All rights reserved
IR Spectroscopy Questions and Correct
Answers
4000-2500 Wavenumbers Ans: X-H Single Bonds
2500-2000 Wavenumbers Ans: Tertiary Bonds, C triple C, C triple
N.
2000-1500 Wavenumbers Ans: C=O and C=C.
1500-500 Ans: X-Y single bonds. Other vibrational modes.
How would you produce an IR spectrum for a homonuclear
diatomic? Why would you need to do this instead of regular IR?
Ans: Use Raman spectroscopy. This is because homonuclear
diatomics have no dipole and so do not absorb IR radiation.
C=C Ans: 1635-1690
Benzene Ans: 1450-1625
NO2 Ans: Symmetric - 1350. Anti-symmetric - 1530.
Ketone Ans: 1715
C triple N Ans: 2250
C triple C Ans: 2100-2250
C-H Ans: 2900-3200
© 2025 All rights reserved