BSc Chemistry SEM V ATKT May 2018-19 ATKT CHEMISTRY ANALYTICAL CHEMISTRY Question Paper - Mumbai University | munotes

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1. Q3 Use of log table/non-programmable calculator is allowed
2. Q1 Answer any four of the following. 20 marks
   • A) Explain the importance of quality concepts in industry
   • B) Arsenic can be determined by titration with iodine solution. The reaction involved is A sample of pure As2O3 weighing 4.0136 g is dissolved in water to make 800 cm? of solution Calculate normality of As2O3 solution used for standardizing iodine solution and convert it into its molarity.[Given: molecular weight of As2O3 = 197.84]
   • C) What is the normality of 69% (w/w) HNOs, having a density of 1.42 cm. Using this HNO3, (69%), how would you prepare 250 cm? 2N HNO3?[Given: molecular weight of
   • D) Discuss the sampling of static liquids
   • E) Discuss any one method of sampling of stack gases, with a labelled diagram
   • F) Explain the importance of chemical standards and certified reference materials in chemical
3. Q2 A) What are metal ion indicators? Discuss its theory and give one example. 20 marks
   • B) Name the different methods to increase the selectivity of EDTA. Discuss any two of these methods in brief
   • C) Calculate the potential at the equivalence point in the titration of 20.0 cm? of 0.1M Fe(II) solution against 0.02M solution at pH=2
   • D) 10.0cm? of 0.1M Fe(II) is titrated with 0.1M Ce(IV) in acidic medium. Calculate the potential on addition of
   • i) of titrant, and
   • ii) 10.1 cm? of titrant
   • E) Discuss the use of diphenylamine indicator in the redox titration, explaining the reactions involved and the function of in such titrations
   • F) Give any five advantages of EDTA, as a titrant
4. Q3 Answer any four of the following: 20 marks
   • A) Discuss the principle of FES
   • B) Distinguish between the following:
   • C) Give any five applications of AAS
   • D) Describe the construction and working of graphite furnace with a labelled diagram
   • E) Discuss the applications of turbidimetry in:
   • a) the determination of molecular weight of macromolecules
   • F) Draw a neat labelled diagram of nephelometer and explain its working
5. Q4 Answer any four of the following 20 marks
   • A) Explain Craig’s counter current extraction with a neat diagram, giving any two
   • B) Discuss the principle and process with reference to solid phase extraction
   • C) Draw a graph of percentage extraction versus pH and explain the concept of [pH] and its
   • D) Draw a neat labelled diagram of a typical HPLC unit and mention the function of any three
   • E) Give any five applications of HPLC
   • F) Name the detectors used in HPTLC and discuss any one of these in brief
6. Q5 A) Answer any five of the following in one sentence. 5 marks
   • a) What are laboratory reagents?
   • b) What is the percentage composition of in sodium hydroxide?
   • c) A solution contains of sugar and 19 mol of water. What is the mole of fraction of
   • d) Give a mathematical expression for size to weight ratio, with reference to sampling
   • e) Name any one device to be used for sampling of particulate solids
   • f) Name the equipment used for sampling of flowing liquid
   • g) What is the colour change at the end point in the redox titration of Fe(II) versus Ce(IV) in the presence of ferroin indicator?
   • h) What is the role of coning and quartering method w.r.t. sampling of solids?
7. Q5 B) Answer any five of the following in one sentence. 5 marks
   • a) What is the criteria for selection of indicator in redox titrations?
   • b) are redox indicators?
   • c) What should be the ratio, in order to see the colour of oxidized form of an indicator in the redox titrations?
   • d) is tris(1,10-phenanthroline)iron (II) sulphate commonly known as?
   • e) Give the general equation representing the formation of metal-EDTA complex
   • f) What is the role of auxilliary complexing agent in direct titrations w.r.t. EDTA titrations?
   • g) Name any one most commonly used standard metal ion solution in back titration
   • h) Give an example of indirect titration with respect to EDTA titrations
   • C) Fill in the blanks: (any five) 05
   • a) Phosphoroscope measures in the presence of fluorescence
   • b) Phosphorimetric experiments are normally carried out at temperature
   • c) A process in which atoms of the element are dislodged from the surface of the cathode and transformed in the gaseous atoms, in hollow cathode lamp is called
   • d) If an atom of higher atomic number is introduced in to a 7-electron system, it
   • e) The function of secondary filter, in fluorimeter, is to absorb radiations
   • f) In AAS, the steady light from hollow cathode lamp is converted in to pulsating current
   • g) Only asmall portion of sample reaches the flame burner in flame photometry
   • (D) State true or False 05
   • a) HPLC separations are carried out at elevated temperature
   • b) Quantity of sample required in HPTLC is more than that in TLC
   • c) HPTLC can simultaneously handle several samples of divergent nature and composition, at given time
   • d) Screw driven syringe type of pump produces pulse free delivery in HPLC
   • e) Thickness of stationary phase in HPTLC is less than that in TLC
   • f) In HPLC, if the composition of the mobile phase changes with time, it is called as
   • g) Only volatile components can be analysed by HPLC

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