BSc Chemistry SEM V 2017 18 2017-18 Analytical Chemistry Paper IV Question Paper - Mumbai University | munotes

Questions asked in this paper

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1. Q3 Use of log table/non-programmable calculator is allowed
2. Q1 Answer any three of the following
   • (A) Explain: 5
   • i)Chi square test, and
   • ii)Confidence limits and its significance
   • (B) Derive equation for a straight line assuming the variables bear a linear 5 relationship to one another, by least square method
   • (C) Discuss any two methods used for the reduction of sample size, in sampling of solids. 5
   • (D) Achemist obtained the following two sets of observations for the percentage of iron in the 5 ore by two independent methods. Use the variance ratio test to determine whether the results from one method are statistically more precise than those of the other
   • i)Null hypothesis, and
   • ii)Q-test
   • (F) briefly: 5
   • i)Ambient sampling , and
   • ii)Sampling of flowing liquid
3. Q2 Answer any three of the following
   • (A) What is chromatography? Discuss the classification of chromatographic methods based on 5 the principle involved
   • (B) the following w.r.t TLC. 5
   • a) Preparation of chromatoplates, and
   • b) Any three applications of TLC
   • (C) the role of mobile phase in paper chromatography? Write the criteria for the 5 selection of solvent system in paper chromatography
   • (D) Write a note on precolumn & analytical column,as used in HPLC. 5
   • (E) What is the role of detector in HPLC? Discuss the UV detector used in HPLC, mentioning its 5 Describe the methods used in applying sample on the HPTLC plates. Give any two limitations 5 of HPTLC technique
   • Q.P. Code : 20461
4. Q3 Answer any three of the following
   • (A) Explain the use of hollow cathode camp, with a labelled diagram, giving its any one 5
   • (B) Discuss the principle of flame photometry. 5
   • (C) Mention any four applications of fluorimetry & discuss any two of these applications. 5
   • (D) Draw aneat labelled diagram of nephelometer and explain nephlometric calibration curve. 5
   • (E) Describe construction and working of graphite furnace with a labelled diagram. 5
   • (F) the basis of choice between turbidimetry and nephelometry. Explain turbidimetric 5
5. Q4 Answer any three of the following
   • (A) Discuss the use of ferroin as an indicator in the redox titration of Fe2* versus Ce**? 5
   • (B) on synergistic solvent extraction. 5
   • (C) Describe the technique of Craig’s counter current extraction with a neat labelled diagram. 5
   • (D) the process of extraction of metals by chelation giving suitable examples, w.r.t. 5
   • (E) Draw aneat labelled diagram of a double beam spectrophotometer and explain the function 5 of each component
   • (F) What do you mean by redox-titration curve? Calculate the potential on addition of 10.5cm3 5 of titrant in the titration of 10.0cm? of 0.1M Fe (IJ) solution against 0.02M at pH=1
6. Q5 (A) the blanks. 4 marks
   • a) Flushing is one of the methods used for sampling of
   • b) The most common fluxes used for decomposition of sample are compounds of
   • c) Equation of Gaussian distribution curve is givenas Y=
   • d)The sample prepared by mixing the increment is called sample
   • (A) State whether the following statements are true or false. 4
   • p) Pyrosulphates are potent basic flux
   • q) Sampling error is found to be inversely proportional to the square soot of the number of
   • r) Samples of gases is more easy as compared to sampling of liquids
   • s)For a sample to be true representative of the bulk, the bulk ratio should be as large as
7. Q5 (B) Fillin the blanks. 4 marks
   • a)The sample volume required in than in TLC
   • b)Separation of solutes in HPTLC takes place by the phenomenon of
   • c)In paper chromatography, the relative position of migrated spots on the chromatogram is
   • Q.P. Code : 20461
   • d)In HPLC, when a single solvent of constant composition is used for separation, the technique
   • (B) State whether the following statements are true or false. 4
   • a) The developed spots are less diffuse in TLC than that in paper chromatography
   • b) Post chromatographic derivatization is possible in HPTLC
   • c) Solvent consumption is less in HPTLC as compared to TLC
   • d) HPTLC can simultaneously handle several samples of divergent nature & composition at a
8. Q5 (C) Fill in the blanks. 4 marks
   • a)Most commonly used radiation source in fluorimeter is lamp
   • b)A calibration curve, in flame photometry, is a plot of against concentration
   • c) The function of secondary filter, in fluorimeter, is to absorb radiations
   • d)Phosphoroscope in the presence of fluorescence
   • (C) State whether the following statements are true or false. 4
   • p) Phosphorescence is not readily observed at room temperature
   • q) In AAS, absorption of radiations by ground state atoms follows Beer’s law
   • r) When test solution is complex in character, calibration method is preferred for quantitative analysis in flame photometry
   • s) Life time of phosphorescence is much larger than fluorescence
9. Q5 (D) the blanks. 3 marks
   • a) Crown ethers is a generic name given to macrocyclic containing ethylene bridge
   • b)Unsaturated organic compounds absorb radiations in the region
   • c) Ina UV- visible spectrophotometer, cuvettes made up of are used in the UV region
   • (D) State whether the following statements are true or false. 3
   • p) In solid phase extraction, substantial waste disposal is a problem
   • q) The function of a detector in a UV visible spectrophotometer is to convert transmitted radiation to electrical signal
   • r) Spectrophotometers operate only in the visible region

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