Discuss different modes of relaxation for an electronically excited molecule using the Jablonski diagram. 

Explain the origin of Rayleigh and Raman lines with the help of an energy level diagram.

Explain the origin of Rayleigh and Raman lines with the help of an energy level diagram.

Calculate the number of vibrational modes for a molecule of methane.

Describe is KBr pelleting method for handling solid samples in IR spectroscopy.

What is the role of a detector in a spectrophotometer? Explain the principle of photomultiplier tube as a detector.

Discuss the factors responsible for the deviation from Lambert-Beer's law.

The UV-VIS spectrum in gaseous phase is observed to be a band spectrum whereas in solution phase it is a smooth and continuous absorption peak. Explain.

Calculate the absorbance and transmittance of a 0.002 40 M solution of a substance having a molar absorptivity of 313 M¹ cm²¹ in a cell with a path length of 2.00 cm.

What is unpolarised light? How can it be polarised?

What is wave number? How is it related to wavelength?

 Discuss the principle of isotope dilution technique

 Explain why (n, y) reaction is most suited for NAA.

In what respects nuclear reactions are different from chemical reactions? Calculate Q value of the reaction 63Cu = (η, γ) 64 Cu. Give that Cu = 62.929590, Cu = 64, 63.929760, n =1.008665 amu.

Describe various types of neutron sources available for NAA. Which one of these is most suitable for trace element analysis?

Explain the basic principle of Differential Scanning Calorimetry (DSC). Draw a block diagram of DSC instrument.

Draw a labelled diagram of the TG curve obtained by heating a mixture of 50 mg of calcium oxalate monohydrate and 50 mg of barium oxalate monohydrate to 1200°C. Calculate the amount of all mass losses.

List the factors affecting TG curve. Taking a suitable example, explain the effect of furnace atmosphere on TG curve.

What are amperometric titrations? Draw common types of curves obtained in amperometric titrations. Briefly discuss their experimental set up.

What is dropping mercury electrode? Give its advantages.