LOYOLA COLLEGE (AUTONOMOUS), CHENNAI – 600 034

B.Sc. DEGREE EXAMINATION – CHEMISTRY

WD 19

SIXTH SEMESTER – April 2009

CH 6606 / 6600 – MOLECULAR DYNAMICS

 

 

 

Date & Time: 18/04/2009 / 9:00 – 12:00     Dept. No.                                                       Max. : 100 Marks

 

 

PART – A

 

Answer ALL questions.                                  (10 x 2 = 20 marks)

 

1. Define the term orbit and orbitals.

 

2. State Pauli’s exclusion principle.

 

3. Define the term degeneracy of an energy level.

 

4. What is Quantum Yield?

 

5. Give the significance of φ².

 

6. Find the value of ln N_A!, ( Where  N_A   is Avagadro’s number )using Stirlings

approximation.

 

7. State the Stark-Einistien’s law.

 

8. Define Chemiluminescence.

 

9. What are thermal reactions? Give an example.

 

10. Mention any two methods of studying fast reactions.

 

PART – B

 

Answer any EIGHT questions.                                               (8 x 5 = 40 marks)

 

11. How is photoelectric effect explained by quantum theory.

 

12. Calculate the radius of the electron in the first orbit of hydrogen atom.

 

13. Derive the expression for the energy of an electron in the n^th shell of hydrogen.

 

14. State the postulates of quantum mechanics and explain any one of them.

 

15. Define the Laplacian operator and Hamiltonian operator.

 

16. Explain Sackur-Tetrode equation and mention the terms involved.
17. A system of N particles has among others, two energy levels with g₁ = 2,

g₂ = 3, E₁ = 41.84 kJmol^-1  and  E₂ = 58.58 kJmol^-1.   Calculate the ratio of the number of particles in the two energy states at 1000K.

 

18. Derive the relation between partition function and energy.

 

19. Explain Photo sensitisation.

 

20. Explain the primary and secondary processes in a photochemical reaction.

 

21. Describe flash photolysis.

 

22. Explain the kinetics of photochemical reaction between  H₂  and  Br₂.

 

PART – C

Answer ANY FOUR questions.                                 (4 x 10 = 40 marks)

 

23. Explain (i) Black body radiation (ii) Separation of partition function.

 

24. Derive the expression of Eigen value ‘E’ and Eigen function  ‘ψ ‘ for a particle

in one dimensional box.

 

25. (i) Derive an expression for translation partition function.

(ii)        Calculate the translational partition function for benzene in a volume of

1 m³ at 25^oC.

 

26. Derive the Maxwell – Boltzmann distribution law.

 

27. Explain any tow of the following

(i)         Radiationless transition.

(ii)        Phosphorescence

• Actinometers
• Zeemann effect

 

28. (i) Derive the Stern-Volmer equation.

(ii)        Explain Jablanski diagram.

 

 

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