IGNOU BCHET-141 June 2022 Previous Year Question Paper

Q1.Distinguish between t-test and F-test.

Q2.With the help of suitable example(s) , differentiate between accuracy and precision.

Q3.(a) What is distribution coefficient ? Write its expression. 2

(b) Briefly explain solvent extraction with the help of a suitable diagram. 3 [ 2 ]

Q4.Discuss the extraction of metal chlorides using solvation giving suitable examples of metal ions.

Q5.(a) Using a flow chart , classify the liquid chromatography into its different types. 3

(b) Differentiate between normal phase and reverse phase chromatography.

Q6.Discuss the principle of col umn chromatography. Explain how will you separate a mixture of two components using column chromatography. Draw a suitable diagram.

Q7.(a) Write the names and chemical structures of any two ion exchangers. 3

(b) What is the operating capacity of a resin ? How is it expressed ?

Q8.Distinguish between molar conductivity and limiting mol ar conductivity. Explain why mobilities of +H and ions are exceptionally high. 5 [ 3 ]

Q9.(a) What are the advantages of a pH metric titration over direct pH metry ? 2

(b) Write any three limitations of standar d hydrogen electrode when it is used for the measurement of potential.

Q10.Taking a suitable example, explain the effect of furnace atmosphere on TG curve.

Q11.(a) Define electromagnetic radiation and give any one characteristic parameter of its wave description. 2

(b) List the different modes of interaction of electromagnetic radiation and matter and describe the processes involved.

Q12.(a) The molar absorptivity of a substance is 5 1 1 31.0 10 cm mol dm . Calculate the absorbance of

Q13.0 10 mol 3dm solution of the substance taken in a cuvette of path length 1.0 cm. 2

(b) List the five essential components of a UV - Vis instrument. What is the role of monochromotor in it ? 3 [ 4 ]

Q14.(a) Calculate the n umber of vibrational degrees of freedom for chloroform molecule, 3CH Cl . How many of these would be bending modes ? 2

(b) Answer any three of the following : 3

(i) What is the necessary condition to observe IR spectra ?

(ii) What are overtones ?

(iii) What is fingerprint region ?

(iv) Why cannot w e use glass cell for IR spectrometry ?

Q15.(a) List the characteristic parameters of an atomic spectral line. What determines its position ? 2

(b) State the merits and limitations of flame atomic emission spectrometry. 3 Give any three applications of flame atomic emission spectrometry. 2022 -141

(ii) (flow chart) 5 1 1 31.0 10 cm mol dm

Q16.0 cm

Q17.0 10 mol 3dm UV-Vis 3CHCl

(i) IR

(ii)

(iii)

(iv)