TYBSc Chemistry Sem 6 Apr. () Analitycal ( Units) .apr. (pc.) Question Paper PDF 2026 - Mumbai University | munotes

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1. Q1 Attempt any four of the following: Describe three mechanisms responsible for the transport of dissolved species to and 5 from the electrode surface in polarography What are the advantages and limitations of a dropping mercury electrode? 5 C Ina polarographic analysis of the following results were obtained. 5
   • 6.34 mA , D= 6.2 X m= Calculate the concentration of Cd*? in the sample solution The following data were obtained from the polarographic analyses of standard Pb*? 5 Two aqueous samples from the Silver valley area were analysed and gave of
   • 7.75 and 30.01 respectively. What are the Pb** concentrations in these two E With the help of a labelled diagram, describe rotating platinum electrode. Give any 5 one of its limitation F Explain: a) use of gelatin in polarographic analysis. 3
   • b) with an example any one type of titration curve obtained in 2 Attempt any four of the following: Explain the principle of GC. 5 How do gas-liquid and gas-solid chromatography differ? 5
   • C. Explain flame ionisation detector in GC. Give one advantage. 5 The retention times of two components X and Y on column were found to be 3.45 5 min and 5.16 min respectively. Calculate 1) HETP for each peak, i1) number of theoretical plates for each component, if the width of the two peaks is 0.42 and
   • 0.63 min. respectively and the time for mobile phase was 0.18 min. with the length of the column as 0.231 m E What is ion exchange chromatography? Give any four ideal properties of resin. 5 F Define ion exchange capacity. How can the ion exchange principle be applied to 5 demineralisation of water?
2. Q3 Attempt any four of the following: Discuss pasteurization and pH control as methods of food preservation. 5 Write the nutrients present in milk and discuss the detection of any four adulterants 5 Describe Cole’s Ferricyanide method to estimate reducing sugars in honey. 5 D_ What is the role of chicory in coffee? Discuss the analysis of coffee for caffeine. 5 Write the composition of face powder and describe a method to estimate amount of 5 calcium and magnesium in face powder complexometrically F Discuss: a) ash analysis of lipstick and 3
   • b) the constituents present in antiperspirants 2
3. Q4 Attempt any four of the following: Discuss the factors that influence the TG curve. 5 Draw a schematic diagram of DTA set up and discuss any three of its components. 5 Explain: a) TGA curve of CaC204. 3 Discuss the application of TGA for the determining the percentage composition of 5 mixture of calcium oxalate and magnesium oxalate Describe the experimental set up for thermometric titrations and explain its 5 application in the titration of boric acid against NaOH F Explain the significance of any five parameters w.r.t. validation of analytical 5
4. Q5 A true or false (any five) 5 marks
   • a) Oxygen gas is bubbled through the experimental solution prior to polarographic Amperometric titrations may lead to inaccurate results due to co-precipitation
   • c) KCl is added as a supporting electrolyte in polarography
   • d) In polarography, DME is used as non-polarisable electrode
   • e) The rotating platinum electrode, can be used at positive potential upto + 0.9V
   • f) The diffusion current is directly proportional to the concentration of electroactive
   • g) Anon-polarisable electrode will have its own potential
   • h) The magnitude of diffusion current is also known as wave height
5. Q5 B Select the correct option (any five) 5 marks
   • a) Theoretical plates are used to
   • i) estimate the efficiency of a column ii) determine the thickness iii) measure the distribution of the analyte between mobile phase and stationary phase
   • b) InGC, is used for electron capture detector
   • c) The affinity for the resin increases as the charge on the ion
   • d) Anion exchange resin is a polymer containing groups as an integral part of the resin
   • e) Smaller the size of the hydrated ion, affinity of the resin for the ions will
   • i)be more ii) be less iii) remain same
   • f) In columns a thin layer of adsorbent is coated to the inner walls of
   • 1) open tubular ii) packed iii) both (4) and (ii)
   • g) Band broadening due to concentration gradient within the band is known as
6. Q5 C State true or false (any five) 5 marks
   • a) Salts of sulphur dioxide are used as preservative for fruits
   • c) Determination of lactose in milk by Lane Eynon method involves a redox reaction
   • d) Polyphenols are adulterants in tea
   • e) The role of mannitol in determination of boric acid titrimetrically, is to maintain the
   • f) Antiperspirants can act as deodorants
   • g) Food treated with irradiation during preservation does not become radioactive
   • h) The action of sodium salt of benzoic acid as preservative is pH dependent Select the correct option (any five) 5
   • a) How many peaks are seen in the DTA curve for dehydration of CuSO4.5H20?
   • b) In the application of DTA, which of the following parameters is measured for
   • c) What do the horizontal flat plateaus in the TGA curve indicate?
   • i)weight loss ii)melting process 11) no weight change
   • d) Which of the following process can be studied by DTA?
   • i)phase of molecule vibrations in molecules iv) none of these
   • e) Which of the following option is appropriate for TGA and DTA?
   • 1)TGA and DTA measure only weight measures only weight while DTA measures other factors as well
   • ii) TGA and DTA measure only temperature
   • iv) TGA measures only temperature while DTA measures other factors as well
   • f) Which of the following is the essential condition for thermometric titrations?
   • iii) no change in enthalpy iv) none of these
   • g) Select the false statement from the following? validation is an integral part of good analytical practice
   • 11) Method validation can be used to judge the quality, reliability and consistency of analytical results
   • ii) Method validation is not required for established methods revised to

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