LOYOLA COLLEGE (AUTONOMOUS), CHENNAI – 600 034

B.Sc. DEGREE EXAMINATION – CHEMISTRY

THIRD SEMESTER – APRIL 2012

CH 3503 – MAIN GROUP ELEMENTS & SOLID STATE CHEMISTRY

 

 

 

Date : 26-04-2012              Dept. No.                                        Max. : 100 Marks

Time : 9:00 – 12:00

 

PART – A

 

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

 

1. When sodium is shaken with naphthalene in nonaqueous solution, it turns paramagnetic.

Why?

2. Explain why Mg(OH)₂ is a weaker base than NaOH.
3. What are fullerenes? How are they prepared?
4. What are aluminates?
5. How is sodium thiosulphate prepared?
6. Give the preparation of Caro’s acid.
7. What happens when dichlorine monoxide is dissolved in water?
8. What are pseudohalogens? Why are they called so?
9. Distinguish between amorphous and crystalline solids.
10. What are Miller indices? Sketch the plane in a cube having Miller indices 110.

 

PART – B

 

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

 

11. How are peroxides and superoxides formed by s block elements? Comment on their

magnetic properties.

12. How does Beryllium differ from other elements of Group 2? Discuss the main points of

difference.

13. How is ozone prepared? Establish its structure.
14. Apply Wade’s rules to B₄H₁₀ and predict the structure.
15. How is nitric oxide prepared? How does it react with acidified potassium permanganate?
16. Write a note on three dimensional silicates.
17. How is orthophosphoric acid prepared? Write its structure.
18. How is available chlorine in bleaching powder determined?
19. How are chlorine dioxide and iodine pentoxide prepared?
20. Draw the projection of unit cells of zinc blende and explain the salient features of its

structure.

21. Derive Bragg’s equation.
22. Write a note on Frenkel defects and its consequences.

 

 

PART – C

Answer any FOUR questions:                                                                             (4 x 10 = 40 marks)

 

23. What are carbides? How are they classified? Explain with an example for each class.
24. a) How are organometallic compounds of lithium prepared? Mention their synthetic

applications.                                                                                                                              (6)

1. b) What happens when alkali metal oxides react with water? How does the basic

strength of hydroxides of alkali metals vary down a group?                                             (4)

25. a) How are hydrazine and hydrazoic acid prepared?   (5)
26. b) Give a brief description of sulphides of phosphorus.                                                       (5)
27. a) Write briefly on bismuth trioxide and pentoxide.    (4)
28. b) Give a brief account of phosphatic fertilizers.                                                                     (6)
29. What are interhalogen compounds? How are they classified? Explain the structures

of ClF₃ and IF₅.

28. a) Describe any two types of cubic unit cells among the Bravais lattices. Calculate the

number of atoms per unit cell in each case.                                                                          (6)

1. b) Show that the limiting radius ratio for an octahedral site is 0.414.                              (4)

 

 

 

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