DB 11

LOYOLA COLLEGE (AUTONOMOUS), CHENNAI – 600 034

B.Sc. DEGREE EXAMINATION – CHEMISTRY

FIFTH SEMESTER – November 2008

CH 5506 – TRANSITION ELEMENTS AND NUCLEAR CHEMISTRY

 

 

 

Date : 05-11-08                     Dept. No.                                        Max. : 100 Marks

Time : 9:00 – 12:00

PART – A

 

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

 

1. Explain Goldschmidt thermite process.
2. List out two uses of vanadium
3. Orbital contributions to magnetic moments of lanthanide ions are significant. Why?
4. The +3 oxidation state is the characteristic oxidation state of lanthanides. Account for.
5. Write the IUPAC names of i.[Co(NH₃)₅CO₃]Cl ii.Na[B(NO₃)₄].
6. [Zn(NH₃)₄ ] ²⁺ cannot be a square planar complex. Why?
7. What is K-electron capture?
8. Write down the mathematical expression of Geiger-Nuttal’s rule.
9. Bring out the relationship between the efficiency of a nuclear reaction and nuclear cross section.
10. Why is technetium 99 m is used for diagnostic purposes ?

 

 

PART – B

 

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

 

11. How is potassium dichromate prepared?
12. Give an account of toxicity of mercury.
13. Describe the methods of separation of lanthanides.
14. Write briefly on the oxidation states exhibited by actinides. Why do they have greater tendency to

form complexes compared to lanthanides?

15. Explain EAN rule and predict the formula of chromium carbonyl assuming that it obeys EAN rule.
16. Sketch the possible geometric isomers for [Cr(NH₃)₂Cl₄ ]^– .Which of these will exhibit optical

isomerism?

17. For the complex ion, [Cr(H₂O)₆]²⁺, the pairing energy is found to be 23500 cm^-1. The value of Δo is

13900 cm^-1. Calculate the crystal field stabilization energy for the complex in weak field and strong

field states.

18. Write a note on the applications of radioactive isotopes in agriculture and biology.
19. Describe the functioning of scintillation counter.
20. What is binding energy? Explain with an example.
21. Describe the process of spallation.
22. What is isotopic dilution analysis? How is it carried out?

 

 

PART – C

 

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

 

23. Explain how titanium is extracted from its ores. Mention two used of titanium. (10)
24. What is lanthanide contraction? What are its consequences? (10)

 

25. a. What are the postulates of valence bond theory, as applied to coordination compounds? Bring out

its defects.                                                                                                                                    (6)

1. Draw VB diagram and indicate the type of hybridization in [Ni(CN)₄]^2-                                   (4)
2. a. How are d-orbitals split, when a transition metal ion is placed in i. an octahedral field and
3. a tetrahedral field?    (5)
4. With the help of crystal field theory explain the given values of magnetic moments of the

following complexes:  i. K₃[Fe F₆ ]  5.9 μ (B.M)    ii. [Ni(H₂O)₆]Cl₂  2.8 μ (B.M.)                   (5)

27. Discuss the nuclear shell model and mention the defects of such a model.
28. Write notes on : i. Nuclear fusion and ii. Theory of β decay.  (5+5)