Nuclear and Environmental Chemistry — DU B.Sc (hons) Chemistry Previous Year Question Papers

(a) (b) (c) Attempt six questions in all. If an atom of 235U92 undergoes nuclear fission reaction after absorbing a slow moving neutron, then 98X40 and 136Y52 are produced. What other particles are produced ? Calculate the binding energy per nucleon for an oxygen atom with atomic mass 15.994910 amu. (Given : neutron = 1.008665 amu, proton = Explain the working and principle of an ionization chamber. 5,5,5 (a) What is artificial transmutation ? Give the nuclear reactions induced by neutron, proton and -particles. (b) Compare nuclear fission and nuclear fusion with examples. (c) Draw and describe the binding energy per nucleon vs. mass number curve. What does its shape indicate about nuclear stability ? 5,5,5 (a) Explain the construction and working principle of a fast breeder nuclear reactors. (b) Explain the following to describe the structure and stability of the nucleus : (i) Meson theory (ii) Liquid Drop Model (c) Derive a relation between half-life and decay constant. What is the order of a radioactive disintegration process ? 5,5,5 (a) Explain the formation of ozone in the stratosphere through photochemical reactions. Discuss the role of chlorofluorocarbons (CFCs) behind ozone depletion. (b) What are SPMs ? How do they cause harm to human beings ? What is the significance of PM2.5 and PM10 in air quality monitoring ? (c) Compare and contrast the environmental impacts of CO, NOx and SOx. Describe methods used to estimate the concentration of any one of these air pollutants. 5,5,5 What is the mechanism of PAN formation in photochemical smog ? Evaluate the working principle and efficiency any two of the following air pollution control devices : (i) Settling Chamber (ii) Venturi Scrubber (iii) Electrostatic Precipitator (ESP) What are air pollutants ? Describe the major types of air pollutants, giving examples of each and their sources. 5,5,5 Explain the hydrological cycle in detail. How can water pollution disrupt this cycle ? What are the major sources of water pollution ? Classify pollutants based on their nature and provide examples of each. Enlist and explain the various techniques for measuring water pollution. (At least three) 5,5,5 Define DO. How is DO measured in a water sample ? Compare and contrast reverse osmosis, ion exchange and electro-dialysis as water purification methods. How can industrial waste be managed to reduce water pollution ? Discuss preventive and treatment-based strategies. 5,5,5 8. Write short notes on any three of the following : (a) Nuclear Waste Management (b) Group Displacement Law in Radioactivity (c) Scintillation Detector (d) Carbon-dating Technique 5,5,5