BSc Chemistry SEM V 2018 19 2018-19 Chemistry IV Analytical Chemistry Question Paper - Mumbai University | munotes

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1. Q3 Use of non/programmable calculator is allowed
2. Q1 Answer any three of the following: 15 marks
   • A) Discuss the sampling of heterogeneous liquids and flowing liquids
   • B) Two different methods were used for analysis of magnesium from a given sample The results obtained gave percentage of magnesium as follows The combined standard deviation is 0.03% Determine whether the two methods differ statistically or only numerically (Given ttable=2.78, for 95% probability level)
   • C) Following results were obtained in the determination of chromium in colorimetric measurement If sample containing chromium gave an absorbance of 0.196, obtain the amount of chromium in the
   • D) Discuss the sampling of gases by displacement method, with a neat labelled diagram
   • E) Give a brief account of confidence limit and confidence interval
   • F) Describe a method for rejection of doubtful values in a set of measurements
3. Q2 Answer any three of the following: 15 marks
   • A) Give the classification of chromatographic method based on the phases involved with one example of each type
   • B) Explain the following w.r.t TLC: a) spotting of development of chromatoplate
   • C) Discuss the applications of paper chromatography
   • D) Explain the functions of pump in HPLC. Name any two types of pumps in HPLC giving an advantage and a limitation of each type
   • E) Draw aneat labelled diagram of UV detector used in HPLC, discuss its working and gave its
   • F) Write any five applications of HPTLC
4. Q3 Answer any three of the following: 15 marks
   • A) Discuss the principle of AAS
   • B) Draw diagram of flame photometer and describe any three factors affecting intensity of
   • C) Give any five applications of flame photometry
   • D) Explain: a) turbidimetric titrations, and
   • b) phase titrations
   • E) Derive a mathematical relationship between the intensity of fluorescent radiations and concentration of the solution
   • F) Draw diagram of turbidimeter and explain turbidimetric calibration curve
5. Q4 Answer any three of the following: 15 marks
   • A) Draw a neat labelled diagram of double beam spectrophotometer and explain the function of its
   • B) What are redox indicators? Discuss the use of ferroin indicator in the redox titration of against
   • C) Calculate the potential at the equivalence point in the titration of 10.0cm? of 0.1M solution against 0.02M solution at pH=1
   • D) Discuss the principle of solid phase extraction. Give any two advantages of solid phase extraction
   • E) Discuss principle and applications of Craig’s counter current extraction
   • F) Explain the role of complexing agent in solvent extraction
6. Q5 A) Fill in the blanks: 4 marks
   • a) The minimum sized packages in the consignment which the sample may represent is called
   • b) For dissolution of silicate rock samples, acid is mainly used
   • c) The most common fluxes used for decomposition of sample are compounds of
   • d) Equation of Gaussian distribution curve is Y =
   • A) State true or false: 04
   • p) Auger sampler is used for sampling of compact solids
   • q) Sampling error is found to be directly proportional to the square root of number of samples
   • r) Coning & quartering method is used for the reduction of particle size
   • s) Mixing of increments give sub-sample
   • B) Fill in the blanks: 04
   • a) In paper chromatography, value is used to identify separated components
   • b) Development of chromatogram requires time in TLC than paper chromatography
   • c) The HPLC, if the composition of mobile phase is same then it is called as elution
   • d) Thickness of the stationary phase in HPTLC is than that in TLC
   • B) State true or false: 04
   • p) The mode of separation in case of paper chromatography is adsorption
   • q) Separations by TLC are sharper than that of paper chromatography
   • r) HPLC separations are carried out elevated temperature
   • s) Post chromatographic derivatisation is possible in HPTLC
   • C) Fill in the blanks: 04
   • a) The process in which atoms of the element are dislodged from the surface of the cathode and transformed in to gaseous atoms, in hollow cathode lamp is called
   • b) Phosphoroscope measures in presence of fluorescence
   • c) In AAS, the steady light from hollow cathode lamp is converted into pulsating light by
   • d) Life time of phosphorescence is than fluorescence
   • C) State true or false: 04
   • p) Phosphorescence is not readily observed at room temperature
   • q) The choice of nephelometry and turbidemetry depends on the fraction of light scattered
   • r) Flame serves as a radiation source for different elements in AAS
   • s) of higher atomic number is introduced into an electron system, it enhances
   • D) Fill in the blanks: 03
   • a) The phenomenon of extraction in which two reagents, when used together, extract a metal ion with enhanced efficiency compared to their individual action is called
   • b) Calibration curve, in UV-visible spectrophotometry is a plot of against concentration of solution at a wavelength
   • c) In the redox titration of v/s K2Cr207, diphenylamine is first oxidized to colourless substance known as
   • D) State true or false: 03
   • p) Grating are made up of non-corrosive materials
   • q) UV-visible spectra is normally used for detection of functional groups
   • r) One of the factor influencing extraction with crown ethers is size of the cation

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