Veer Narmad South Gujarat University 2011-1st Sem M.Sc Chemistry S-3485 : - 04 - 1( Part - 1 ) ( ) ( Self Finance) - Question Paper
S-3485
M. Sc. (Sem. I) (Self Fin.) (IC, PC & EC) Examination March / April - 2011 Chemistry : Paper - IV
(Instrumental & Chemical Analysis)
Time : 3 Hours]
[Total Marks : 70
Instructions :
"x Seat No.:
6silq<3i Puunkiufl [qaim SuwiA u* qsq Fillup strictly the details of signs on your answer book.
Name of the Examination :
M.Sc. (Sem. 1) (Self Fin.) (IC, PC & EC)
Name of the Subject:
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-Section No. (1,2......): NIL |
(2) All question are compulsory
(3) Figures to right indicate full marks of that question
(4) Draw neat diagrams where necessary
K* and jitn* electronic transitions.
Answer any three, (a) (1) Describe %
18
(2) Explain the terms hypsochromic shift, bathochromic shift.
(b) (1) Explain the effect of polar solvents in uv absorption
spectra of phenol.
(2) State the selection rules for uv absorption and limitations of Beer - Lambert Law.
(c) (1) With neat diagram describe in brief the functions
of each component of double beam IR spectrophotometer.
(2) How do you distinguish primary secondary and tertiary amines on the basis of IR spectra ?
(d) (i) Describe the sampling methods for solids in IR
spectroscopy.
(ii) Explain fundamental vibrations and overtones.
(e) (i) Name the detectors used in IR spectrophotometer
and explain working principle any one.
(ii) A solution of a compound in ethanol shows an absorbance 0.52 at 286 nm in a cell with a 1.0 cm path length. Its molar absorptivity in ethanol at that wavelength is 12600 mol/L. What is the concentration of compound.
Answer any three: 18
(a) (i) Explain spin-spin coupling in NMR with suitable
example.
(ii) Name the reference material used in H'NMR .Give its advantages.
(b) (i) Explain magnetic anisotropy in benzene.
(ii) Explain chemical shift with its unit and scale. Mention factors affecting chemical shift.
(c) (i) Discuss in brief .principle of mass spectrometry.
(ii) What major fragments are formed in mass spectra
of anisole.
(d) (i) Discuss chemical ionization method.
(ii) explain the terms : base peak ,parent peak and M+l peak.
(e) (i) Explain the terms : Larmor frequency and
precessional orbit.
(ii) What peaks in mass spectra can distinguish between :
ch3
(l) CH:, - CH- CH2 - CH2 - CHS and (ii) CH., -CH2 -CH-CH2 -CH3
ch3
Answer any three : 18
(a) (i) Discuss the criteria for selecting solid stationary
phase in GC.
(ii) Explain the terms Resolution and Retention time.
(b) (i) Give van dempter plot equation and explain the
significance of various terms.
(ii) Discuss the kinetic variables affecting zone broadening.
(c) (i) Describe different types of columns used in GC.
(ii) Discuss the factors affecting the efficiency of the
chromatographic column.
(d) (i) Explain any one sample injection system in GC .
(ii) Describe the working of ECD detector.
(e) (i) Describe interfacing of GC-MS.
(ii) Explain the terms selectivity factor exclusion limit.
4 Answer any four : 16
(a) (i) Calculate the Xm;ix in uv region for the following compounds applying wood ward fisser rules
(b) Distinguish between each pair with its appropriate vibrations in IR spectra :
(i) CHS - CH2 - CHO and (o C-CHg
(ii) Toluene and p-xylene
(c) Identify the compound from H'NMR spectral data
Molecular formula = 1.21 (3H) triplet = 1.93 (3H) singlet
5 = 4.03 (2H) quartet
(d) What is Me lafferty rearrangment ? Explain with suitable example.
(e) Write brief note on :
(i) plate theory of chromatography
(ii) Electrophoresis
S-3485] 3 [ 100 ]
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Attachment: |
| Earning: Approval pending. |
