CS MAINS 2014 ·.CHEMISTRY (Paper I).


Calculate the radius ratio (rc ra in an octahedral lattice. Explain why lithium salts crystallize in octahedral lattice, although radius-ratio values are much below the expected ratio.

Point out the main features of the Valence Bond and Molecular Orbital" theories. For the H2 molecule, write down the wave function using
Valence Bond theory
Molecular Orbital theory
st improvements to the wave functions.

Calculate the entropy change involved in the isothennal reversible expansion of 5 moles of an ideal gas from a volume of 20 L to a volume of 200 L at 300 K.

The density of acetone at 30°C is 0-83 gmL-I. Cal.culate the surface tension of acetone, given that the paraehor values of 0 and the double bond are 8.2, 16.3, 19.5 and 21-5 respectively.


For a particle confined in a one-dimensional box of length L(O calculate the values of the average position x and momentum

Deduce the Born-Lande" equation for 'lattice What modifications are imposed on this for better results?

Draw the molecular orbital diagrams for N2 and NO. Based on the diagrams, find the bond orders and comment on the' magnetic properties of the two.

How high will a liquid rise in a capillary tube of 0.4 mm diameter, if its density is 1·3 x 103 kgm-3 and surface tension 8·5 x 10-2 Nm-f 9.8

During the clectrolysis of a solution of potassium chloride between platinum elcctrodcs, 0.0145 g of the chloride were lost from the anodic compartment and 0·0875 g of silver was deposited in a silver coulometer connected in series with the cell. Detennine thl; transport number of and Cl- ions.

Draw the radial part of the wave function and radial -probability distribution for hydrogen atom for Is, 2s and 2p orbitals.

What is the basic difference betwet;n Schottky and Frenkel dcfects in ionic crystals? How "do solids with such defects differ from non-stoichiometric compounds

Draw and explain curves showing the variation of first and second ionization energies for the elements from H to Nc.

The enthalpy of decomposition of gaseous water per mole at 20°C and 1 atm pressure is 243·05 kJ. Calculate its value at 80°C, given the following data:
Cp 44·26, Cp(H2) 29·56, Cp 32·15 JKpl mOrl

What do you mean by the terms eigen functions and eigen values' Which of these functions is/are eigen functions of the d/dx operator?

exp exp sin 25 x2

What isl are the eigen valuels 20

Calculate the number of components, and number of .phases, and evaluate the number of degrees of freedom for the following equilibria:

An iceberg floating in a lake, considerin'g the lake, iceberg and atmosphere as one system.
N20lg) NO2(g)
Pure partly frozen acetic acid
NaCl(s) KC1(s) H20(l) H20(g) system
NaBr(s) KCl(s) H20(l) H20(g) system


Show that for a gas obeying tIie van der WaaJs equation:

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Specify the basis of the Irving-Williams series and arrange the Zn2+ and Ni2+ ions according to this series.

Specify the basis of.the trans effect and arrange ci, NH3, CN, and H20 in this sequence. 10

What are the salient features and limitations of the ,Crystal Fiqld theor;? Show .the splitting of the d6 ion in weak and strong fields in an octahedraI environment.

Explain 'lanthanide contraction' underlying its'relevance in periods other than 4f. 10

Calculate <img src='./qimages/260-5d.jpg'> for the second order reaction, 2 N02(g) 3 at 400 K. Given: Arrhenius factor A 2·5 x I09 S and the energy of activation is 121 kj mol-I. 10

Distinguish between the above
and dark reactions
Fluorescence and phosphorescence 10

In the following sequence of reactions, identify the products
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How are iron-proteins classified? What arc the various functions performed by iron ii1 biological systems? 10

For the photochemical reaction A 1·5 x 10-5 moles of B were formed on absorption of 6·2 J at 360 nm. Calculate the quantum efficiency. 10

Discuss the geometrical and optical isomerism in octahedral complexes of the type ·M(A and where A-Aand A-B are bidentate ligands. 10

Point out the special structural features of the following compounds:

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Decomposition of a gas is of second order. It takes 60 min. for 60% of the gas. to be decomposed, when its initial concentration is 4.5 x 10-2 mol L-I. Calculate the specific reaction rate. 10

Comment on the spectroscopic and magnetic properties of· 4f elements. 10

Show the various photochemical processes and their approximate rate constants on a Jablonski diagram. . 10

Draw the contours of the five d orbitals. Show how <img src='./qimages/260-7e.jpg'> bonds are formed with metal d-orbital participation. 10

"Si04 tetrahedra fonn the framework of all silicates, including silica (SiO2)." Justify this statement with appropriate framework strctures of ortho, pyro, cyclic, infinite chain, sheet and silica.

Calculate the room temperature (300 ratio of the rate constants for two reactions that have the same A value but have Ea values that differ by 5 kJ mol 50 kJ mol-I.

Derive Langmuir's'.Adsorption Isothenn and explain how it could be used for detennination of the surface area of an adsorbent.