BABSc, B.Com & BCA Questions _III - Nalanda Open University

Nalanda Open University
Annual Exam-2010,
Bachelor of Science (Chemistry) Hons, Part-III
Paper-VI
Time: 3 Hrs Full Marks: 75
Answer any FIVE questions. All questions are of equal marks.
1. (a) Give an outline of how SchrÖdinger Wave equation is used to arrive at
the shapes of orbital via radial and angular distribution curves.
(b) Show that the energy of a particle in one-dimension potential box is
quantized.
2. Explain the terms. Probability and radial probability of electron in an atom.
Draw radial probability distribution curves for s and p orbital.
3. Draw and explain the molecular orbital diagram of H + 2 molecule ion, He 2 and
Li 2 molecule. Evaluate their bond orders and comment on magnetic behaviour of
each one.
4. Write critical short notes on any THREE of the following.
(a) Electromagnetic wave and matter wave.
(b) Bond strength of N 2 and F 2 molecule in term of MOT.
(c) Anti-bonding and non-bonding orbital.
(d) Possible orientations for the orbital in the f sub-shell.
5. How the solvents have been classified? Compare the merits of liquid sulphur
dioxide and water as solvents. Under what conditions sulphur dioxide acts as a
neutral solvent?
6. Name the ores of platinum. Give flow-sheet diagram for the extraction of
platinum from Sudbury ore. Discuss important properties, types of platinum
metals and their use. Why is platinum called noble metal?
7. Explain how the atomic orbital combine to form bonding and anti-bonding
molecular orbital? What are the limitations of such combination?
8. (a) By giving suitable examples, differentiate a symmetry element from
symmetry operation.
(b) Show that NH 3 and BF 3 are placed in different symmetry point groups.
9. Explain in brief diamagnetic and paramagnetic. Write macroscopic and
microscopic causes of such magnetic behaviour.
10. Elaborate role of sodium, potassium and magnesium in plants and animals.
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