BCHET-141 EM 2025 SOLVED ASSIGNMENT

Description

ASSIGNMENT
ANALYTICAL METHODS IN CHEMISTRY
Course Code: BCHET-141
Assignment Code: BCHET-141/TMA/2025
Maximum Marks: 100

Note: Attempt all questions. The marks for each question are indicated against it.

Par A (50 marks)
1 Writ the procedure for the sampling of soil samples. (5)
2 Define determinate errors. How we can reduce them. (5)
3 What is significance of F-test? Explain using a suitable example. (5)
4 Briefly explain the extractions with diphenylthiocarbazone. How is change in pH useful in
such extractions?
(5)
5 Discuss the extraction of an organic compound when it is present in the aqueous phase
along with the impurities.
(5)
6 How is extraction of metal chlorides and nitrates carried out using solvation? (5)
7 How can a mixture of three components be separated using ascending paper
chromatography? Draw the suitable diagram and explain.
(5)
8 Give at least five examples each of mobile phases and locating agents used in paper
chromatography
(5)
9 Briefly explain various factors affecting the efficiency of column chromatography (5)
10 Why is selectivity coefficient of an ion exchanger important? Give the order of selectivity
coefficients of different cations and anions.
(5)
Par B (50 marks)
11 Drive an expression for the ‘operational definition of pH. (5)
12 Discuss design and working of calomel and glass electrodes. (5)
13 Describe different factors effecting conductance. (5)
14 A conductivity cell shows a resistance of 3950 Ω at 25oC when filled with the
experimental solution and 4864 Ω at the same temperature when filled with 0.02 M KCl
solution. If the conductivity of the solution is 2.767 x 10-3 S cm-1, calculate the
conductivity of the experimental solution.
(5)
15 Describe the experimental setup of TGA. Taking suitable examples explain the
effect of furnace atmosphere on TG curves.
(5)
16 An impure sample of CaC2O4H2O is analyzed using TGA technique. TG curve
of the sample indicates the total mass change from 85 mg to 30.7 mg when this
sample was heated up to 1173 K. calculate the purity of the sample.
(5)
17 (a) Define electromagnetic radiation and state the relationship between the
velocity and wavelength of an electromagnetic radiation.
(b) Molecular spectra are band spectra whereas atomic spectra are line spectra.
Explain.
(2)

(3)
18
(a) State Beer and Lambert’s law and write its mathematical expression.
(2)
(b) What are monochromators? Explain the working of prism monochromator
with the help of a suitable diagram.
19
20
(a) Calculate the number of vibrational degrees of freedom for ethane, C2H6,
explain the fingerprint and functional group regions in IR spectrum.
(b) Outline the advantages of premix burner in atomic spectroscopy.
Discus structure of a laminar flow flame showing various zones.
List different excitation sources used for atomic emission spectrometry.
Discuss the interferences observed in flame atomic emission Spectrometry
(3)
(3)
(2)