LOYOLA COLLEGE (AUTONOMOUS), CHENNAI – 600 034

M.Sc. DEGREE EXAMINATION – CHEMISTRY

FIRST SEMESTER – APRIL 2012

CH 1807 – CONCEPTS IN INORGANIC CHEMISTRY

 

 

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

Time : 9:00 – 12:00

 

          Part – A

 

Answer all the questions                                                                                (10 x 2 = 20)

 

1. Calculate the effective nuclear charge felt by a 3d electron of iron atom(z = 26).
2. Why is the electron affinity of nitrogen almost zero while that of fluorine high?
3. Which among the following is readily soluble in water (a) CaCO₃ (b) K₂CO₃? Give reasons.
4. What is F- centre?
5. Why is the bond angle in water less than that of methane?
6. Why is the bond length of O₂²⁺ less than that of O₂?
7. Why is the molecular weight of acetic acid found to be doubled when determined by colligative method?
8. What are clathrates? Give an example.
9. What is the role of sodium metal in liquid ammonia? Give any two applications.
10. Differentiate spinel and inverse spinel structure of oxides.

Part – B

Answer any eight questions                                                                           (8 x 5 = 40)

11. Define the following and explain their trends in a period and in a group.
12. a) electron affinity b) ionisation energy
13. How is electron affinity determined by constructing Born-Haber cycle for NaCl?
14. Explain with examples, the factors favouring the formation of covalent character in ionic compounds.
15. Predict the structure of the following molecule/ion using VSEPR theory.

(i) XeF₂                            (ii) ICl₄^–.

15. How are clathrates prepared? Mention their uses.
16. Explain Why the bond order of NO⁺ is higher than that of NO .
17. What are intermolecular forces? How do these forces originate?
18. Explain the role of liquid ammonia in i) acid- base reactions ii) complexometric reactions.
19. Explain the acid-base concepts by Lux-flood and solvent system concept.
20. What are Miller indices? Sketch the planes in a cube with Miller indices a) 111 b) 110             c) 112          d) 312
21. Describe the three types of cubic unit cell among the Bravais lattices. Calculate the number of atoms per unit cell in each case.
22. What is radius ratio rule? Discuss the structure of zinc blende.

 

                                                                  Part – C

 

Answer any four questions                                                                                    (4 x 10 = 40)

23. How is lattice energy calculated theoretically? What are the factors that affect lattice energy?
24. Discuss in detail the following types of defects in crystals. a) Schotky defects b)Frenkel defects
25. c) metal deficiency defect d) metal excess defect.
26. Explain the magnetic property of CO is diamagnetic using M.O theory.
27. Explain the band theory of metals. How does this theory explain the conductance behaviour of metals?
28. Explain the Pearson’s concept of hard and soft acids and bases, with examples. Discuss any three applications of this theory.
29. Describe the basic principles involved in X-ray diffraction studies.

 

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LOYOLA COLLEGE (AUTONOMOUS), CHENNAI – 600 034

M.Sc. DEGREE EXAMINATION – CHEMISTRY

FIRST SEMESTER – NOVEMBER 2012

CH 1813/1807 – CONCEPTS IN INORGANIC CHEMISTRY

 

 

Date : 05/11/2012            Dept. No.                                        Max. : 100 Marks

Time : 1:00 – 4:00

 

Part-A

Answer all questions. Each question carries two marks:                                                           10×2=20

 

1. For two ions of the same size and charge one with an (n-1)dxns0electronic configuration will be more polarizing than a cation with a noble gas configuration (n-1)s2(n-1)p6ns0. Illustrate with an example.
2. Illustrate isolabel relationship with an example and mention its significance.
3. What are thermochemical radii? How are they calculated?
4. What is Madelung constant? How is it calculated for the rock salt structure?
5. Both Cu(I) and Cu(II) are stable, whereas Ca(I) is unstable and is readily oxidized to Ca(II). Explain.
6. KI with a small enthalpy of hydration (-611 kJ mol-1) is soluble in water, but CaF2with a large enthalpy of hydration (-6782 kJ mol-1) is insoluble in water. Offer a resonable explanation.
7. Both trigonalbipyramidal and square pyramidal geometries involve dsp3 hybridization: what is the difference between these two?
8. What are ionic liquids? How are they classified?
9. What are superacids? Cite an example.
10. Illustrate leveling effect with an example.

 

Part-B

Answer any eight questions. Each question carries five marks:                                                     8×5=40

 

11. Derive Born-Lande equation to compute lattice energy. How is a more accurate measure of lattice energy obtained?
12. Explain the polarity of covalent bond between two hetero atoms in the light of MO theory with the aid of MO energy level diagram.
13. In molecules where variable hybridization is possible, different bond lengths are possible. Illustrate with an example.
14. Give an account of the general structural features of ionic compoundswith unitcell diagrams.

15a.  What is critical radius ratio? Mention its significance.

1. Calculate the size of the octahedral hole in a lattice of closest packed anions.
2. What is the principle of conservation of atomicorbitals? Account for the electronegativity difference between atoms in a molecule with the aid of qualitative MO energy level diagram.
3. Explain the influence of bond pair and lone pair electrons in determining the structures of SF₄ and NH₃.
4. Give an account of imperfection in crystal lattices.
5. What are proton sponges? How do they affect basicity?
6. Discuss the solvolysis and precipitation reactions in liquid ammonia.
7. Give an account of the unique properties of sulfuric acid as a solvent.
8. Explain (a) apicophilicityand (b) symbiosis with examples.

 

Part-C

Answer any four questions. Each question carries ten  marks.                                                  4×10=40   

 

23a.  Schematically represent s– and p-molecular orbitals formed by the overlap of p-orbitals.

1. The ionization energy of NO is 894 kJ mol-1and the nitrosyl ion (NO+) is stabilized and exists in several compounds. Explain with the help of a qualitative MO energy level diagram.
2. How does the MO energy level diagram of NO differ from that of BeH₂?

 

24a.  What are electron density counter diagrams? How is the effect of polarization illustrated with theaid of such diagrams?

1. How does hybridization affect electronegativity of atoms in molecules? Illustrate with an example.

 

25a.  Explain the Band theory of metals and account for the metallic properties.

1. How do you account for covalent character of ionic compounds? Cite experimental evidences to illustrate such a property of ionic compounds.

 

26a.  What are inclusion compounds? How are they classified?

1. Explain the structural features of gas hydrates and describe their applications.

 

27a.  Explain HSAB principle? Mention the factors which influence the hardness of a chemical species.

1. Write a note on the donor acceptor number of solvents.

 

28a.  Describe Lux-Flood and Usauovich concepts of acids and bases.

1. Discuss the classification of acids and bases.

 

 

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