INSTRUMENTAL METHODS OF ANALYSIS

INSTRUMENTAL METHODS OF ANALYSIS Question Papers (2008, Aug/sep,supple)

SET : 1

1. (a) Define the terms qualitative and quantitative analysis. (b) Differentiate between micro and semi-micro analytical methods. (c) What are advantages and limitations of chemical methods.

2. Compare and contrast the techniques phase contrast microscopy and differential interference contrast microscopy (DIC).

3. Explain the following terms:
Gravitational force
Centrifugal force
Sedimentation coefficient.
4. You have two samples of DNA derived from different organisms, A and B. DNA from A shows an increase in optical density beginning at 70 C and plateau at 80 C. DNA from B shows a corresponding increase in O.D beginning at 65 C and plateau out at 76 C. what is your conclusion. Justify your answer.

5. (a) Define fluorescence. Derive an expression relating intensity of fluorescence and concentration.
(b) Write a brief note on:
Triplet state
Doublet state
Singlet state
6. (a) Discuss the basic principle of infrared spectroscopy? (b) Briefly describe the scanning of infrared spectrum of an organic compoung.

7. Explain the following:
Free inductive decay
Hetero nuclear decoupling
Off resonance coupling
Chemical shift
8. Give an account on electronic structure and hyperfine splitting in ESR spectroscopy?

SET: 2

1. Give a brief account on methods for reporting analytical data?

2. Compare and contrast the optical magnification obtained by the bright and dark field microscopy along with their specific applications.

3. (a) Give the basic principle involved in analytical centrifugation. (b) What are the important applications of this technique in biochemistry?

4. You have two samples of DNA derived from different organisms, A and B. DNA from A shows an increase in optical density beginning at 70 C and plateau at 80 C. DNA from B shows a corresponding increase in O.D beginning at 65 C and plateau out at 76 C. what is your conclusion. Justify your answer.

5. (a) Define optical activity? What is the principle involved in circular dichroism spectroscopy? (b) Differentiate polarimetry and circular dichroism.

6. Discuss the principle, importance and applications of mass spectrometry?

7. (a) Give the principle underlying in NMR spectrometry? (b) Describe the component of a NMR spectrometer with a neat labeled diagram.

8. (a) What is the principle of ESR. Discuss some important applications of ESR. (b) What are the limitations of ESR.

SET :3

1. Give an account of the instruments involved in electrochemical methods of analysis along with their principle of working.

2. (a) Give the basic principle involved in the viewing an object in dark field. (b) Draw a neat labeled diagram of optical pathway of dark field microscope. (c) Give its specific use.

3. (a) Give the basic principle involved in analytical centrifugation. (b) What are the important applications of this technique in biochemistry?

4. What are the different regions of the electromagnetic spectrum and where are they used for?

5. Define the following terms:
Chiral compounds
Cotton effect
Circular birefringence.
6. How will you distinguish between intermolecular and intramolecular hydrogen bonding by IR spectroscopy?

7. (a) Explain the principle involved in CMR spectra? (b) Why it is not possible to determine relative ratio of carbon atoms in a compound by integration of peak areas in 13C NMR as in PMR?

8. Why ESR spectroscopy is widely used in the study of chemical, photochemical and electrochemical reactions? Justify your answer.

SET: 4

1. Write an account on analytical methods based on the physical property measurement?

2. Narrate the principle of operation of a fluorescence microscope. Give its applications in biology?

3. Calculate the molecular mass of the protein where the sedimentation coefficient of the protein is 7.75 * 10 power -12 s. In subsequent analysis the protein was found to have an average diffusion coefficient of 4.0 * 10 power -11 Sq.mt per sec. and the partial specific volume of 0.734 * 10 power -3 cub.mt per kg.
Convert the molecular mass to relative molecular mass.
express the molecular mass in Daltons.
4. Define the terms:
(a) (i) Radiant power (P)
(ii) Path length of radiation
(iii) absorptivity
(iv) molar absorptivity
(b) Describe and derive the Beer's law.
(c) What are its limitations and deviations.

5. (a) What is atomic absorption. What are its advantages and disadvantages. (b) Give some of its limitations.

6. (a) What are the different regions of infrared radiation? (b) Explain various types of streching and bending vibrations with suitable examples.

7. (a) why does a signal for a particular set of protons in split into a multiplet. (b) Explain with suitable examples the term spin-spin coupling.

8. (a) Which of the following two formula is correct for the complex obtained between copper ion and 8 quinolinethanol (C9H7N5)
(i) Cu(I) (C9H7N5) (C9H6N5)
(ii) Cu (II) (C9H6N5)2.
Show that the ESR approach is appropriate for this determination.
(b) Which is one of the best known free radicals used in calibrating ESR spectra?
INSTRUMENTAL METHODS OF ANALYSIS Question Papers (Regular, 2007)

Wednesday, October 15, 2008
SET : 1
1. Give an account of the instruments involved in the electrochemical methods of analysis along wuth their principle of working.
2. Narrate the principle of operation of a fluorescence microscope. Give its applications in biology?
3. A protein has a sedimentation coefficient value of 3.12 × 10-13 sec in water. Its diffusion coefficient in water is found to be 8.2 × 10-7 /cm. both the above values have been corrected for 20C in water. The partial specific volume of the protein is 0.735, & the density of water at 20C is 0.9982. Determine the molecular weight of the protein?
Explain the principle involved in the above method.
4. Discuss the effect of hydrogen bonding in UV absorption. Explain by taking example.
What is the effect of electronegativity in UV absorption. Explain by taking examples of methyl chloride & methyl iodide.
5. What are fluorometric reagents? Mention some important fluorometric reagents.
How is fluorometric is used in the determination of thiamine in a meat sample?
6. Write short notes on :
a) Brainbridge mass spectrograph
b) Dempsters mass spectrometer
7. Write a brief account on :
a) Pulse – acquired method
b) Fourier transform method
c) Multidimensional NMR
8. Why electron spin resonance is also called electron paramagnetic resonance?
Calculate the ESR frequency of an unpaired electron in a magnetic field 0.33τ. Given, for electron g = 2 and β = 9.273 × 10-24 J/T
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LABELS: INSTRUMENTAL METHODS OF ANALYSIS (IMA)
INSTRUMENTAL METHODS OF ANALYSIS Question Papers (supple,2006)
POSTED BY M.S.CHOWDARY AT 12:38 AM
SET:1
1. What are the instrumental methods? How are they classified? Name two or three instrumental methods for each of the physical property.
2. (a) Write briefly about origin and theory of UV spectroscopy
(b) What are the various components of UV spectrophotometer and discuss each of them in detail and briefly the scanning of UV spectrophotometer?
3. Write short notes on the following UV applications:
(a) Quantitative analysis
(b) Molecular weight determination.
(c) Impurities in organic compounds.
4. (a) What are the advantages in atomic absorption of a heated graphite atomiser over a flame atomiser.
(b) Why are spectral interferences less severe in atomic amsorption and atomic flourescence spectroscopy than in flame emission spectroscopy?
(c) What is the purpose of densitometer and how is it used in qiantitative determination.
5. Explain the analytical applications of emission spectroscopy with examples.
6. Comment on:
(a) Relaxation time
(b) Magic number
(c) Tetramethyl silane and its significance
(d) Multiplicity in NMR
7. Discuss ESR instrumentation with a block diagram.
8. Out of syllabus(so not mentioned!)
SET: 2
1. (a) Distinguish between accuracy and precision.
(b) What are determinate and indeterminate errors
(c) Write briefly about determinate and indeterminate errors.
(d) Distinguish between relative and absolute error.
2. (a) What are different regions of infra red radiation? Explain various types of stretching and bending vibrations with suitable examples.
(b) What is force constant? How is it determined? To what use is it put?
3. (a) What is the difference between molar absorptivity and absorbance?
(b) An absorbance of 0.436 was obtained after 11.5 ml of titrating agibt was added to 68ml of an initial solution. What was the corrected absorbance of the solution? What would be the % error have been if the correction was not made?
(c) A water solution of a coloured compound has a molar absorptivity of 3200 at 525nm. Calculate the absorcance and % transmittance of a3.40 * 10-4 solution if a 1.0 cm
4. (a) Write the advantages of atomic absorption spectroscopy over flame emission spectroscopy?
(b) What is a single beam and a double beam atomic absorption spectrophotometer and explain the instrumentation involved?
(c) Define sensitivity and detection limits in atomic absorption spectroscopy.
5. (a) Explain the function of a monochromater.
(b) How plasma emission is used for analytical purpose?
6. Write short notes on
(a) Longitudinal relaxation
(b) Transverse relaxation
(c) Spin-Spin coupling.
7. Out of syllabus
8. Out of syllabus
SET: 3
1.
(a) Define sensitivity and detection limits
(b) Give the detection limits of
1. IR Spectrometry
2. UV Spectrometry
3. NMR
4. Mass Spectrometry
(c) What are the advantages and disadvantages of chemical and instrumental methods.
2. Write short notes on:
(a) Molar extinction coefficient
(b) Laws of absorption
(c) Photometric titrations
(d) Photometric accuracy
3. Write short notes on the following UV applications:
(a) Chemicals kinetics
(b) Charge transfer transitions
(c) Dissociations constants of acids and bases
4. Write short notes on:
(a) Total consumption burner
(b) Premix burner
(c) Nebulizers
5. (a) Explain how the output is detected.
(b) Explain how two lines are separated.
6. (a) What is spin-spin splitting?
(b) A methylene group (CH2) is adjacent to a CH group. Into how many peaks is the CH2
peak split by the single adjacent hydrogen?
7, 8 out of syllabus.
SET:4
1. Repeat (set 2 - Q1)
2. (a) why far U.V region is called vacuum ultra region
(b) discuss the advantages and disadvantages of spectrophotometry in vacuum-ultra violet region of the spectrum.
(c) why are the absorption bands appear instead of sharp lines in UV spectra
3. Repeat (set1 – Q3)
4. (a) in atomic absorption, the elements such as Al, Ti, Mo, V, Si can not be detected when a flame is used to produce the atomic state. Why?
5. Explain the analytical applications of emission spectroscopy with examples
6. Draw a schematic of an NMR instrument and discuss the parts.
7. Out of syllabus
8. Out of syllabus