LOYOLA COLLEGE (AUTONOMOUS), CHENNAI – 600 034
M.Sc. DEGREE EXAMINATION – FOOD CHEMISTRY
FIRST SEMESTER – April 2009
WD 56
FP 1802 - APPLICATIONS OF SPECTROSCOPY
Date & Time: 28/04/2009 / 1:00 - 4:00 Dept. No.
Max. : 100 Marks
PART – A
Answer ALL the questions
(10 x 2 = 20)
1. Summarize the relationship between the force constant k, the bond energy, and the
vibrational frequency.
2. Compare the relative stretching frequencies for C-C, C=C and CC bonds.
3. What is the main difference between atomic absorption spectroscopy and
flame
emission spectroscopy?
4. What are auxochromes? Give examples.
5. Account for : 14NH3 gives broad signals and 15NH3 gives a sharp doublet.
6. Differentiate between chemical shift and coupling constant.
7. State nitrogen rule.
8. Define metastable peak. Identify the amide which gives a strong peak at m/e=44.
9. Write any five differences between NMR and ESR
10. Predict the total number of peaks of anthracene negative ion in ESR spectra
PART – B
Answer any Eight questions
(8 x 5 = 40)
11. Predict the number and give the names of fundamental modes of vibrations of the
following
i) CO2
ii) H2O
12. Describe the uses of group vibrations in the structural elucidation of metal
complexes of urea and thiocyanide.
13. a) What condition must be met for absorption of ir radiation by a molecule?
b) Select the diatomic molecules that do not absorb in the ir from the following :
HCl, N2, ClBr, O2, H2
14. a) State the selection rules for electronic transition.
b) How does solvent polarity influences shift in wavelength?
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15. Give an account of the various types interferences in flame photometry.
16. How will you determine calcium and magnesium in water using AAS?
17. Cyclohexane shows only one chemical shift at room temperature while at low
temperature there are two. Explain.
18. What are the factors which affecting the chemical shift? Explain the anisotropic
effects of π electron circulation in alkyne and aromatic ring systems.
19. How many kinds of H’s are there in
c) C6H5NO2
a) CH3CH2CH3
b) (CH3)2CHCH2CH3
d) C6H5CH3
20. Write in detail the general fragmentation modes in mass spectrometry.
21. Discuss the fragmentation modes responsible for prominent peaks in the mass
spectrum of benzyl alcohol.
22. Discuss the principle of Photo electron spectroscopy.
PART – C
Answer Any Four questions
(4 x 10 = 40)
23. How the various geometrical isomers of tetrahedral and octahedral complexes can
be distinguished from their IR spectra?
24. Describe the instrumentation of flame photometer with a block diagram.
25. Discuss the applications of NMR to inorganic compounds.
26. a) Explain the rules for predicting prominent peaks in mass spectrum.
(6)
b) The mass spectrum of 1-hexanol gives a base peak at m/e= 56. Account the
presence of this peak.
(4)
27. Discuss the hyperfine splitting of a) methyl radical b) p – benzosemiquinone
radical anions
28. How is high spin and low spin iron complexes determined by quadrupole splitting
using Moss Bauer spectroscopy?
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