Time Allowed: 3 hours Maximum Marks: 300
Candidates should attempt Question Nos. I and 5 which are compulsory, and any three of the remammg questions selecting at least one question from each Section Assume suitable data lf conSidered necessary and mdicate the same clearly
1.Answer any three of the folloWlng
(a)Explain how paramagnetism of 02 molecule can be accounted for by Molecular Orbital(MO)theory whereas Valence Bond theory predicts it to be diamagnetic

(b)Given evidence to establish that sodium chloride (NaCl) has fcc structure but caesium chloride (CsCl) has bcc structure.
(c)Lanthanides are generally trivalent hut Ce4+ and Eu are more stable. Explam this observation

(d)Why ethylenediamme forms much stronger complexes With transition metals as compared to NH3, even though both are N-donors?

2.(a)Define bond order, bond strength and bond length, and differentiate between them Explian with suitable examples as to how these are interrelated with each other.
(b)What is ferrocene? Draw its structure and explain its characteristic bonding features.(15)

(c)Explam the difference between homogeneous and heterogeneous catalySis with a suitable example for each

3.(a)Write sailent features of stop-flow and relaxation methods for studying fast reactions

(b)What do you understand by thermodynamlc and kinetic stability of complexes? Give suitable examples for each. 20
explain the following briefly: 20
metal atom clusters
Fuel cells
BET lSotherm
Quantum yield

4.(a)Explain the difference between consecutive and chain reaction The rate constant for the reaction C2H6->7 2CH3 iS 1.57 X 10 3 s universe at 1000 K. Calculate the rate constant for the backward reaction, if delta fG0 for CH3(g) lS 159.74 kJmol Kp 1.083 X 10 ll and 0.0831 L bar K universe mol universe(30)
(b)What are fluxional molecules? How are these characterized?
(c)Draw the shuctures of cytochromes and ferredoxins explaining their functions in biologiCal systems.(15)

SEcnON B
Answer any three of the folloWlng
(a)Compare the solvent behaviour of liquid ammonia with that of water especially with regard to solvolysis, redox and complexometric reactions
(b)Electronic spectra of coordination compounds cannot be explained by valence bond theory and it is essential to conSider splitting in d-orbitals. Justify.(20)

(c)What do you understand by entropy of a system? How it increases With increasing temperature delta S becomes zero at absolute zero temperature? 20)

Explain the free energy change in a Galvanic cell generating positive e.m.f What happens
when it iS
drained off?

6.(a)Draw the shapes of d-orbitals. How do these split up in the presence of octahedral and tetrahedral fields? Explain the relationship between CFSE for the two geometries. Calculate the magnetic moments of FeSo4.6H2O and [Ni(NH3)6]SO4 and predict their geometry
(b)Explain the basic principle of polarography. Write ilkoviC equation explaining all the terms
and show that diffusion on current is directly proportional to concentration

(c)What do you understand by liquefaction of gases? Explain critical temperature and critical pressure. Draw schematic diagram for liquefaction of air
7.(a)Explain Aufbau pnnclple, Hund's rule of maXimum multiplicity and Pauli's exclusiOn principle What is their SIgnificance In writing e1ectronic configuration? Give suitable examples 20)
(b)Explam Hess's law Calculate the enthalpy change for the reaction HCl(g) NH3(g) NH4Cl(s) Given that <img src='./qimages/1082-7b.jpg'>
(c)How liquid crystals are different from solid crystals? Compare their characteristic features
8.(a)How metal carbonyls are syntheSized? What are the characteristic features of metal-carbon bonding in carbonyls? Draw the structures 0f and Cr(CO)6

(b)Explam ionization, coordination, linkage and optical iSomerism in coordination compounds with a suitable example for each.
(c)what do you understand by imperfection in crystals? Explain various types of defects and resulting change in properties