BSc Chemistry SEM V 2016 17 2016-17 Analytical Chemistry IV Question Paper - Mumbai University | munotes

Questions asked in this paper

• (2) Figures to the right indicate full

1. Q1 Answer any three of the following :
   • B) A volumetric analysis for calcium ions on triplicate samples of blood serum of a patient gave the following data : What is the 95% confidence interval for the mean of the data, assuming :
   • a) no additional information about the precision of the method is known, and
   • b) a large number of measurements have given o = 0.056 mmo! of calcium ions [Given : t= 4.30, and z= 1.96 at 95% confidence level]
   • C) Define sampling. Explain the sampling of immiscible liquids
   • D) The following table gives the dependence of'y' Assuming a linear relationship between the variables, derive an equation of the type y = mx + c by least square method
   • E) Describe random and non-random sampling
   • F) Discuss the sampling of compact solids
2. Q2 Answer any three of the following 15 marks
   • A) Mention various steps involved in HPTLC. Write any two advantages and
   • B) Discuss the following TLC
   • ii) Any two applications
   • C) Name any two detectors used in HPLC. Draw a neat labelled diagram of any one of these detectors, mentioning any two advantages
   • D) Give any five applications of HPLC
   • E) Define R, value. Explain the classification of chromatogaphic techniques based on phases involved, giving examples of each type
   • F) Explain the different methods used for locating the separated components in
3. Q3 Answer any three of the following 15 marks
   • A) labelled diagram of AAS and give the function of each component
   • B) Discuss total consumption burner, mentioning its function, with a neat labelled diagram. State the factors which control the temperature of the flame of
   • C) Derive a mathematical relationship between intensity of fluorescent radiation and the concentration of the solution
   • D) Give any five applications of AAS
   • E) Draw a neat labelled diagram of a turbidimeter and explain tubidimetric
   • F) Explain: i) turbidimetric titration, and 4, any three of the following :- 15
   • A) 10.0 cm? M ferrous ion solution is titrated with 0.1M ceric ion solution Calculate the potential of the system at
   • i) half the equivalence point, and (ii) the equivalence point 0.770V and +4. 1.44V]
   • B). Draw a neat labelled diagram of a double beam spectrophotometer. Give the function of any two components
   • C) Explain the important analytical applications of UV-Visible spectroscopy
   • D) Explain the extraction of metal ions by chelation
   • E) What is the principle of Craig's counter current extraction. With the help of neat diagram, describe Craig's apparatus
   • F) Write an informative note on 'solid phase extaction’
4. Q5 A) Fill in the blanks 4 marks
   • a) The peak of normal error curve indicates
   • b) In F test, 'F' is defined as the ratio of . of two sets of observations
   • c) Gaussian distribution curve is a plot of relative frequency of error against
   • d) The sample prepared by mixing the increments is called . sample
   • A) State true or false 4
   • p) The value of Pearson's correlation coefficient, close to -1 indicates that the dependent variables and independent variables are not linearly related
   • q) In the least square method, the sum of squares of deviations of all the points should be maximum
   • r) Sample containing boron is stored in borosilicate glass
   • s) For dissolution of acidic samples, basic fluxes are used
5. Q5 B) Fill in the blanks 4 marks
   • a) technique, the components of the mixture are carried through the stationary phase by the flow of . phase
   • b) If two or more solvents which differ in polarity, are employed in HPLC, it is known as . elution
   • c) The role of precolumn is to remove . from solvent to prevent contamination of the analytical column
   • d) In HPLC, separation is carried out at . temparature
   • B) State true or false 4
   • p) HPTLC is a planar chromatographic technique
   • q) Screw driven syringe type pump, produces pulse free delivery in HPLC
   • r) Degassing system is employed in HPLC to remove dissolved gases from
   • s) not quite easy to achieve of R, values in TLC 5.C) Fill in the blanks :- 4
   • a) Fraction of free atoms that are thermally excited is governed by
   • b) In the expression, total amount of light absorbed at v stands
   • c) The phenomenon in which emission of light continues even after the exciting radiation is cut off, is called
   • d) Liquid . is used to cool the sample to enhance the phenomenon of
   • C) State true or false 4
   • q) Iftwo elements present in the sample have absorption at the same wavelength, analysis give erroneous results in AAS
   • r) Phosphorimetry is more sensitive that fluorimetry
   • s) Phosphoriscope can measure phosphorescence in the presence of fluorescence 5.D) Fill in the blanks :- 3
   • a) In redox titrations, colour of oxidised form is seen over reduced form, when
   • b) In the titrations of Fe (II) vs the indicator diphenylamine is irreversibly oxidised to
   • c) In UV-Visible spectroscopy, the calibration curve is a plot of . versus
   • D) State 'True' or 'False' 3
   • p) The cavity and nature of the crown ether greatly influence the extraction
   • q) Tributylphosphate is an example of solvating solvent in synergistic solvent
   • r) Atungsten lamp can be used as a source in UV-Visible spectrophotometer, to

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