LOYOLA COLLEGE (AUTONOMOUS), CHENNAI – 600 034
B.Sc. DEGREE EXAMINATION – CHEMISTRY

SIXTH SEMESTER – APRIL 2006
CH 6600 – MOLECULAR DYNAMICS
(Also equivalent to CHE 600)
Date & Time : 19042006/FORENOON Dept. No. Max. : 100 Marks
PART – A
Answer ALL questions. (10 ´ 2 = 20 marks)
 State the de Broglie relation. Explain the condition under which it is applicable.
 Normalise e^{ax} in the interaval (0,1).
 What are the possible values for angular momentum according to Bohr’s postulate?
 Give the expressions for wave function and energy for the third penergy level of 1,3
 Evaluate ln N! when N = 10^{30} using Stirling’s formula.
 Calculate the number of ways of distributing four particles among five energy levels if the particles are electrons.
 Write Boltzmann equation connecting entropy and thermodynamic probability.
 What is intersystem crossing?
 Define quantum yield of a photochemical reaction.
 Mention any four relaxation methods used in the kinetic study of fast reactions.
PART – B
Answer any EIGHT questions. (8 ´ 5 = 40 marks)
 Determine the kinetic energy of the electrons emitted by a light of 100 nm if the threshold frequency of the metal is 9.0 ´ 10^{14}
 Calculate the ionization energy per mole of H atom.
 Derive the expression for Hamiltonian operator in cartesian coordinates.
 Examine whether “A sin ax” is Eigen function for the second order differential operator. If so, state the Eigen value.
 Calculate the wave length of transition for a conjugate olefin containing 3 double bonds.
 Explain how partition functions can be separated.
 Calculate the ratio of translational partition function of D_{2}(g) to H_{2}(g) at the same temperature and volume.
 Write SackurTetrode equation and mention the terms involved.
 Derive the relation connecting internal energy(E) and molecular partition function(Q).
 Explain the principle of flash photolysis.
 Explain the factors affecting phosphorescence emission.
 Explain photosensitisation with two examples.
PART – C
Answer any FOUR questions. (4 ´ 10 = 40 marks)
 Obtain an expression for the radius of “H” atom on the basis of the Bohr’s model of atom.
 Obtain the expressions for the energy and wave function of a free particle in a one dimensional box.
 State the postulates of MaxwellBoltzmann distribution law and hence derive an expression for most probable distribution.
 Explain any two of the following
(a) Fluorescence and structure
 Kinetics of H_{2}Br_{2} (photochemical) reaction.
 Chemical actinometer.
 Draw Jablonski diagram and explain in detail.
 Derive the following
(a) E = RT^{2}
(b) E_{translation} =