LOYOLA COLLEGE (AUTONOMOUS), CHENNAI – 600 034

B.Sc. DEGREE EXAMINATION – CHEMISTRY

FIFTH SEMESTER – APRIL 2012

CH 5506 – TRANSITION ELEMENTS AND NUCLEAR CHEMISTRY

 

 

 

Date : 27-04-2012              Dept. No.                                        Max. : 100 Marks

Time : 9:00 – 12:00

 

PART – A

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

 

1. Explain why the molar volumes of transition elements are much lower than those of

s block elements of the neighbouring  groups.

2. Give the uses of ferro-vanadium alloy.
3. What are lanthanides?
4. Name any two minerals of actinides.
5. What is co-ordination number? Give an example.
6. What is chelate effect?
7. Define radioactivity.
8. What are pi-mesons and K-mesons?
9. What are radiopharmaceuticals? Give an example.
10. Define critical mass.

PART – B

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

 

11. Explain why most of the transition metals form coloured compounds.
12. How is titanium extracted from its ores?
13. What is lanthanide contraction? Explain any one consequence of it.
14. Explain the isolation of uranium.
15. Explain spectrochemical series. Mention the significance of the series.
16. What are ligands? Explain with an example.
17. Discuss Optical isomerism in coordination complexes with two examples.
18. A freshly cut piece of wood gives 16100 counts of β-ray emission per minute per kg and an

old wooden bowl gives 13200 counts per minute per kg.   Calculate the age of the wooden

bowl. The half-life period of ¹⁴C is 5568 years.

19. Describe the functioning of scintillation counter.
20. Explain the significance of ratio with examples.
21. Explain hydrogen bomb.

 

22. Discuss ‘neutron activation analysis’.

 

PART – C

 

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

 

23. (a) Discuss the toxic effects of cadmium.

(b)  Explain the preparation of  K₂Cr₂O₇.

 

24. (a) Explain the electronic spectra of lanthanide compounds.

(b)  How is neptunium synthesized?   Give its uses.

 

25. (a) Explain the postulates of VB theory of coordination compounds.

(b)  Discuss the geometrical isomerism exhibited by coordination compounds with two

examples.

 

26. (a) Discuss any three evidences to support crystal field theory.

(b)  Calculate the CFSE for octahedral high and low spin for d⁴, d⁷ configuration.

 

27. (a) Explain radioactive displacement law.

(b)  Discuss the liquid drop model of the structure of nucleus.

 

28. (a) Discuss the atomic power projects in India.

(b)  Explain the construction and working of a nuclear reactor.

 

 

 

 

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LOYOLA COLLEGE (AUTONOMOUS), CHENNAI – 600 034

B.Sc. DEGREE EXAMINATION – CHEMISTRY

FIFTH SEMESTER – NOVEMBER 2012

CH 5506 – TRANSITION ELEMENTS AND NUCLEAR CHEMISTRY

 

 

 

Date : 03/11/2012             Dept. No.                                        Max. : 100 Marks

Time : 9:00 – 12:00

 

PART – A

 

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

 

1. How is (CH₃)₂ Hg prepared? Mention one of its uses.
2. Inspite of its high negative electrode potential, chromium is not a reducing agent. Why?
3. Orbital contributions to magnetic moments of lanthanide ions are significant. Why?
4. f-f transitions are used for fingerprinting of Ln (III) ions. Account.
5. Write down the systematic name for each of the following complexes.
6. a) K[Cr(oxal)₂(H₂O)₂] .3H₂O b) [NiCl(en)₂(NH₃)]Cl
7. Draw the geometrical and isomers of [RhCl₂(en)₂]⁺.
8. What is K-electron capture?
9. What are leptons and hardons?
10. What is critical mass with respect to nuclear fission?
11. Why ²³⁸ U is not suitable for nuclear fission reaction?

 

PART – B

 

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

 

11. How is potassium dichromate prepared?
12. Discuss the various oxidations states exhibited by titanium. Which is the most stable oxidation state?
13. How are lanthanides separated by on exchange method?
14. What is lanthanide contraction? What are its consequences?
15. Using VB theory explain the geometry and magnetism of [CoF₆]^3–and [Co(CN)₆]^3– .
16. What is EAN rule ? Which of these complexes obey EAN rule? i.[Zn(NH₃)₄]²⁺ ii. [Co(NH₃)₆]²⁺.
17. How are d-orbitals split, when a transition metal ion is placed in an octahedral field?
18. The half life of ²²⁰Rn is 54.5 s. What mass of this nucleus is equivalent to 1 millicurie?
19. What is binding energy? How is related to the stability of nuclei?
20. Write a note on shell model of the nucleus.
21. What type of materials can be used as moderators and coolants in a nuclear reactor? Explain.
22. How is radioactive dating carried out using carbon-14?

PART – C

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

 

23. How does tungsten occur in nature? How is the metal extracted?
24. Write a note on occurrence, isolation and uses of uranium.
25. Define crystal field stabilization energy. Calculate its value for the following systems and explain.
26. d⁵ low spin octahedral ii.d⁵ high spin octahedral.
27. What are the basic postulates of valence bond theory of coordination compounds. What are its

limitations?

27. Explain the functioning of Geiger counter and scintillation counter.
28. a. Explain the principle and application of neutron activation analysis. (5)
29. Write a brief note on nuclear reactors in India.                                                                       (5)

 

 

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