Analytical Instrumentation-I (INDSC3A) — DU B.Sc. (Hons) Instrumentation Previous Year Question Papers

analysis and outline its pros and cons over classical methods. (7) (b) Write short note on (5) 1. (a) Absorbance of a standard 2 ppm sample in a 1cm Calculate the concentration of an unknown solution (same absorbing species) if the absorbance in the same cuvette is 0.75. (b) What is the difference between colorimetry and spectrophotometry? (2) (c) How is the Rf value defined in the context of chromatography? (2) (d) Polar molecules show low Rf value in paper chromatography. Give a reason. (2) (e) Write down the two factors affecting the column efficiency in column chromatography. (2) (f) Differentiate between classical and instrumental method. (2) 2. (a) Explain the factors affecting the choice of analytical method. (7) (b) What features of HPTLC address the limitations found in standard TLC? (5) 3. (a) What are the shortcomings and challenges associated with using Beer Lambert's law in UV- VIS spectrometry? (7) (b) Explain the principle of paper chromatography and discuss its applications in separating and analyzing mixtures. (5) 4. (a) Compare and contrast thin layer chromatography with column chromatography in terms of methodology and applications. (7) (b) The intensity of incident light on a sample is 0.60 w/m? and the intensity of light entering the detector is 0.40 w/m?. Determine the transmittance and absorbance. (5) 5. (a) Explain how GPC can be used to determine the molecular weight distribution of polymers. Why is this information important? (7) (b) What are the dispersing elements used in UV-Vis spectroscopy applications? Which one is preferred? Give two reasons. (5) 6. (a) Define extraction. Describe any one type of sample extraction technique. (7) (b) Define band broadening in chromatography. Write the equation and explain the terms involved in Van Deemter equation. (5) 7. (a) Describe the instrumental method of quantitative