LOYOLA COLLEGE (AUTONOMOUS), CHENNAI – 600 034

M.Sc. DEGREE EXAMINATION – CHEMISTRY

GH 3

SECOND SEMESTER – APRIL 2008

CH 2809 – CHEMISTRY OF MAIN GROUP ELEMENTS

 

 

 

Date : 22/04/2008            Dept. No.                                        Max. : 100 Marks

Time : 1:00 – 4:00

PART-A

Answer all questions. Each question carries two marks 

1. Differentiate catenation and heterocatenation. The tendency of catenation of Group14 elements decreases from carbon through lead. Comment.
2. Draw the structure of [Si₆O₁₈]^12-.
3. What are torands? Cite an example.
4. Give the structure of corrphycene.
5. What are alumazenes?
6. What are pyrazolylborates? Give an example.
7. The inorganic analogue of benzene is different from the latter in its reactivity. Rationalize.
8. What are metalloboranes?
9. Give the structure of tetrasulfur tetranitride.
10. Depict the structure of cyclotrisilane. Comment upon its photochemical cleavage.

PART-B

Answer eight questions. Each question carries five marks 

11. Give an account of the complexes of alkali metals with crown ethers.
12. Explain the biological roles of ionophores.
13. Give an account of the synthesis of polyhedral borane anions.
14. Explain the synthesis of macrocyclic amines and imines.
15. Explain the structure of pyroxenes. How are they related to amphiboles?
16. Write a note on boron-nitrogen clusters.
17. Give an account of the structure and coordination property of mono- and diphosphine ligands.
18. Write a note on aminophosphanes.
19. Explain the solvolysis reaction involving the halides and organohydrides of boron and aluminium.
20. Explain the methods of synthesizing chlorine fluorides.
21. Give a brief account of the synthesis and application of boron nitrides.
22. Explain a high energy experimental technique used to synthesize inorganic compounds.

PART-C

Answer four questions. Each question carries ten marks 

23a. Differentiate harsh and moderate fluorinating agents of main group elements. Cite examples of each class.

1. Explain the synthetic utility of these fluorinating agents.

24a.  What are isopoly and heteropoly acids?

1. Give an account of the synthesis and structure of  iso- and heteropolymolybdates and tungstates.

25a. What are carboranes? Explain the synthesis of ortho-carborane.

1. Explain the synthesis, structural features, and polyhedral rearrangement of carboranes.
2. Explain the methods of synthesizing fluorides and chlorides of boron, phosphorus, and nitrogen.
3. Explain the complexes of alkali metals with -diketones, crown ethers, and calixarenes.

28a. Explain the structural features of zeolites.

1. Highlight the difference between natural and synthetic zeolites.

Go To Main page