COMPETITIVE EXAMINATION (MAIN)
CHEMISTRY
Paper-I
Time 3 hours Full Marks: 200
Note: Thefigures intheright-hand marginindicatefullmarksforthequestions.

Attempt five questions in all.


Question No. 1 is compulsory.


1. Answer any ten of the following 4xlO=40

Write down the possibleJormula and nature of chemical bond between two atoms A and B with atomic numbers 16 and respectively.


Give the electronic configuration of Fe and Cu2+ .


"To detect chlorine in chlorobenzene, AgN03 is not suitable." Explain.


What is chemical potential? Give the physical significance of it.


Calculate the packing fraction for an FCC unit cell.


fj} How can the order of CL"1 unknown reaction be determined by differential method? Discuss briefly.

State Kohlrausch's law of independent ion migration.


Explain the condition for a molecule to absorb light.


Determine the magnetic moment value from the spin only formula for

high-spin C03 and low-spin Mn2+ ions.
.



Draw the structure of Fe3


Show that an irreversible process leads to entropy production.


Comment on the magnetic properties of potassium ferricyanide and


hexachloronickel(IIj ion.
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2. Answer any eight of the following 5x8=40

What are the factors on which 10Dqvalue of a complex ion depends?


Explain the molecular basis for the difference between the two heat capacities, Cp and Cv.


Under what condition Gibbs' energy change can be considered as equivalent to the enthalpy change in a process? Give the relationship between the equilibrium constant and the standard Gibbs' energy change.


Draw the molecular orbital energy level diagram for CO molecule.


A M solution of A shows 50% transmittance when a cell of 1 cm width is used at wavelength 1.1 nm. Another 0·1 M solution of compound B gives the absorbance value of 0'1761 using the same cell and at the same wavelength. What will be the transmittance of a solution that contains a mixture of 0·1 M each of A and B in the same cell at the same wavelength? (Given: log5


The concentrations of a species A undergoing the reaction A B are

0·25 moldm-3 at time and 3 second{s) respectively. Determine the order of the reaction,


Explain the reaction of sodium metal in liquid ammonia.


Explain the bonding in metal carbonyl complex.


Given the following half-cell reactions


Zn2 E O V
CuI(s) H EO V
Calculate the standard potential, EO of the cell

Zn, Zn2+ II CuI; Cu
Write the conditions for the l}plane in both BCC lattice and FCC lattice to give Bragg diffraction.
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3. Answer any five of the following 8x5=40

Draw the Born-Haber cycle to determine the lattice energy of NaG!.


Explain briefly how to predict the direction of a chemical equilibrium taking temperature and pressure as variable parameters.


Write a short note on both the Frenkel and Schottky defects.

A bacterial colony grows most commonly by cell division. The change in the population due to cell in an actively growing colony is given by dN =Ag Ndt. Derive a mathematical expression for the population of the bacterial colony at any given time. (Assume N No; at zero time)


Write a short note on Jahn-Teller effect.


What is meant by ionic strength of a solution? Calculate the ionic strength of a solution prepared by mixing 50 ml of 0:2 MKNO 20 ml of 0·15 MK2S04 and 30 m1 of 0'05 MCu(N03b.


4. Answer any four of the following 10x4=40

Write briefly about lanthanide separation.


Explain the difference between valence bond theory and molecular orbital theory.


Discuss the Orgel diagram for d 3 and d 4 metal ions.


Explain the quenching of orbital angular momentum to the magnetic .


"
moment in terms of crystal field theory.
(el For a second-order chemical reaction with only one reactant, ,derive a mathematical expression for the concentration of the product at cwY,y time t.
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5. Answer any two of the following: 20x2=40

What is concentration cell with transference? Discuss the working principle of such a cell by taking the following example

Pt, H2 1atIn), HCI(aq)IIHCI(aq), H2 1atIn), Pt


Derive Gibbs-Duhem equation. Give the physical significance of the equation.


Give the different steps involved in free-radical polymerization and hence show that rate of is proportional to the concentration of· monomers and root of the inhibitor concentration.


..
6. Answer any four of the following lOx4=40

Draw the radial wave function plot 2s, and 3p orbitals.


Give two examples and structures af complexes having metal-metal quadrupole bonds.


Give some of the reactions of TIs-cyclQpentadienyl


Give the electronic configuration ofO2 and °2,Arrange them

according to their bond order and bond length. Mention the 1l).agnetic properties of all the species.


Write a note on the magnetic propertief;' of the lanthanide elements.


7. Answer any two of the following 20x2=40

Derive an expression for work done in a reversible adiabatic expansion.


Starting from the collision theory for bimolecular gaseous reaction,

derive a formula for Arrhenius pre-exponential factor in terms of . molecular properties of the reactants.


Compare the lanthanide with tramdtion metals.


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8.
Describe in detail the various defects found in crystals.

9.
Explain in detCliI the d-orbital splitting patterns in a trigonal bipyramidal and a square pyramidal geometry on the basis of crystal field theory. 40


40
10. Starting with the Hamiltonian for a particle moving freely in a I-dimensional box, derive the expression for energy and normalized wave function. Show the plots of some of the wave functions for the system. . Explain the quantization of energy in this case. 40

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