SPECTROSCOPY CH.2,9 EXAM WITH QUESTIONS AND
ANSWERS #9
IR spectroscopy is most useful for distinguishing?
A. Double and triple bonds
B. C-H bonds
C. Chirality of molecules
D. Composition of racemic mixtures - correct answer A
Oxygen (O2) does not exhibit an IR spectrum because?
A. It has no molecular motions
B. It is not possible to record IR spectra of a gaseous
Molecule
C. Molecular vibrations do not result in a change in the
Dipole moment of the O2 molecule
D. None of the above - correct answer C
Which of the following chemical shifts would correspond to an aldehyde proton signal in
a H-NMR spectrum?
A. 9.5 ppm
B. 7.0 ppm
C. 11.0 ppm
D. 1.0 ppm - correct answer A
The isotope 12C is not useful for NMR because?
A. It is not abundant in nature
B. Its resonances are not sensitive to the presence of
Neighboring atoms
C. It has no magnetic moment
D. The signal-to-noise ratio in the spectrum is too low - correct answer C
In 13C-NMR, splitting of spectral lines is due to?
A. Coupling between a carbon atom and protons
Attached to that carbon atom
B. Coupling between a carbon atom and protons
Attached to adjacent carbon atoms
C. Coupling between adjacent carbon atoms
D. Coupling between two adjacent protons - correct answer A
UV spectroscopy is most useful for detecting?
ANSWERS #9
IR spectroscopy is most useful for distinguishing?
A. Double and triple bonds
B. C-H bonds
C. Chirality of molecules
D. Composition of racemic mixtures - correct answer A
Oxygen (O2) does not exhibit an IR spectrum because?
A. It has no molecular motions
B. It is not possible to record IR spectra of a gaseous
Molecule
C. Molecular vibrations do not result in a change in the
Dipole moment of the O2 molecule
D. None of the above - correct answer C
Which of the following chemical shifts would correspond to an aldehyde proton signal in
a H-NMR spectrum?
A. 9.5 ppm
B. 7.0 ppm
C. 11.0 ppm
D. 1.0 ppm - correct answer A
The isotope 12C is not useful for NMR because?
A. It is not abundant in nature
B. Its resonances are not sensitive to the presence of
Neighboring atoms
C. It has no magnetic moment
D. The signal-to-noise ratio in the spectrum is too low - correct answer C
In 13C-NMR, splitting of spectral lines is due to?
A. Coupling between a carbon atom and protons
Attached to that carbon atom
B. Coupling between a carbon atom and protons
Attached to adjacent carbon atoms
C. Coupling between adjacent carbon atoms
D. Coupling between two adjacent protons - correct answer A
UV spectroscopy is most useful for detecting?
