IIT-JAM Chemistry Paper-2006 (X) Br 2 /FeBr 3. (c) CH COCH COOCC H (X) Y. (d) (X) (c)

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1 IIT-JAM Chemistry Paper-2006 CEMISTRY Instruction: Q.1-30 (bjective questions) carry three marks each and Q (Subjective questions) carry fifteen marks each. 1. After the following interchanging of groups in the Fischer projection of 2-bromobutane, the configuration of (X) and (Y) will be C 2 5 C 2 5 C 2 5 (X) (Y) X = R, Y = S X = S; Y = R X = R; Y = R (d) X = S; Y = S C 2. The major product of the reaction 2 /Fe 3 C C C (d) 3. In the reaction sequence C25Na (i) C3 (ii) 2/ C CC CCC (X) Y The product (Y) is: C CC CC C CCC CCC (d) C3CC25 4. The major product (X) in the reaction C3 AlCl 3 C is: (trace of 2 ) 25ºC (X) 3 C (d) 1

2 CEMISTRY 5. The product of the reaction AlCl 3/Cu2Cl2 6 6 heat C C Cl gives positive test with Fehling s solution. The product is: C C ClC C64 C (d) 6 5 C C 6. The compound (X) in the reaction sequence C 2 CNa C 2 CNa S P 2 S 3 heat (X) C 2 C C 2 C 7. The major product of the reaction Rancy Ni C 2 C 2 (d) S + S (d) 8. The increasing order of the acidity of the hydrogen marked in bold italics among the following is: I II III III < II < I II < I < III I < II < III (d) II < III < I 9. The major product of the reaction is: 10. The number of m enantiomers of camphor (d) Four Two Three (d) ne 2

3 11. The decreasing order of the first ionization energy of the following elements is e > > Be > B Be > B > > e > e > Be > B (d) B > Be > e > CEMISTRY 12. If the values of Madelung constants of the following compounds are equal, then their lattice energy values decrease in the order KCl > NaF > Ca > Al 2 3 Al 2 3 > Ca > NaF > KCl NaF > KCl > Ca > Al 2 3 (d) Al 2 3 > Ca > KCl > NaF 13. The fluoride, whose value of dipole moment is NT equal to zero, is: XeF 4 CF 4 SF 4 (d) PF The decreasing order of ionic nature of the following compound is: Lil > Na > KCl > CsF Lil > KCl > Na > CsF CsF > Na > KCl > Lil (d) CsF > KCl > Na > Lil 15. The atomicity and the total number of bonds in the elemental white phoshorus molecule are respectively, 4 and 6 6 and 4 4 and 4 (d) 6 and The octahedral crystal field splitting 0 of d orbital energies of the follwoing metal ions decreases in the order Co Co Rh Rh Co Co Rh Co Co (d) Co Co Rh 17. The half-life of a radioactive nuclide is 20 years. If a sample of this nuclide has an activity of 6400 disintegrations per minute (dis/min) today, its activity (dis/min) after 100 years would be (d) The average value of C C bond order in graphite is: 1 3/2 3/4 (d) 4/3 19. The optical absorption spectrum of [Ti( 2 ) 6 ] 3+ has its absorption maximum at cm 1. The magnitude of the crystal field stabilization energy in cm 1 is: (d) In inorganic qualitative analysis, 2 S in acidic medium will NT precipitate. gs ZnS CuS (d) CdS 21. The phase diagram of a pure substance is sketched below. P P3 P2 P1 T The number of degrees of freedom at points P1, P2 and P3, respectively, are 2, 1, 0 1, 2, 0 2, 0, 1 (d) 0, 2, The solubility products (K sp ) for three salts MX, MY 2 and MZ 3 are , and , respectively. The solubilities of these salts follow the order MX > MY 2 > MZ 3 MZ 3 > MY 2 > MX MZ 3 > MX > MY 2 (d) MY 2 > MX > MZ 3. 3

4 CEMISTRY 23. The temperature (T) dependence of the equilibrium constant (K) of a chemical reaction is correctly described by the following statement: For an endothermic reaction, the slope of ln K vs 1/T plot is positive. For an exothermic reaction, K is proportional to T. For an exothermic reaction, K at a higher temperature is lower than K at a lower temperature. (d) If is independent of temperature, the change in K with T is smaller at lower temperatures. 24. When the concentration of K + across a cell membrane drops from 0.01 M to M, the potential difference across the membrane is: 0.0 V V V (d) 0.59 V 25. The statement that is correct for both electrochemical (galvanic) cells and electrolytic cells is G nfe Free energy decreases in both cells. The cell potentials are temperature independent (d) Chemical energy is converted into electrical energy in both cells. 26. The molar heat capacity at constant volume of a colourless gas is found to be 25 J.mol 1 K 1 at room temperature. The gas must be N 2 2 C 2 (d) S 2. 1/2 27. The wavelength for a particle (moving in a ring) is 2 exp2i probability of finding the particle in a small interval d when the value of d d / 2, where is the polar angle. The / 2 is: dexp i (d) dexp i / An electric current of ampere is passed for 2000 seconds through a solution containing Cu C3CN 4 and metallic copper is deposited at the cathode. The amount of Cu deposited is mol 0.01 mol 0.02 mol (d) 0.04 mol 29. The Maxwell-Boltzmann distribution for molecular speeds is shown in the following figure. f( v) W L In the figure, is the height of the peak, L is the location of the maximum and W is the width at half height. As the temperature is decreased, increases, L deceases and W increases increases, L decreases and W decreases. decreases, L decreases and W increases (d) decreases, L decreases and W decreases. 30. A system undergoes two cyclic processes 1 and 2. Process 1 is reversible and process 2 is irreersible. The correct statement relating to the two processes is: S (for process 1) = 0, while S(for process 2) 0 cycle q 0 for process 1 and cycle q 0 for process 2. More heat can be converted to work in process 1 than in process 2. (d) More work can be converted to heat in process 1 than in process 2. v 4

5 CEMISTRY 31. Identify reagent (P) and write the structure of products (Q, R, S and T) in the following series of the reactions. N 2 NC [P] ClS 3 N 3 [Q] [R] + / 2 (i) N 3 / 2 S 4, 20ºC (ii) + / 2, heat [S] [T] (Anitbacterial) 32. For the reaction C C C + K(aq) C 6 5 (dextro) (i) What is the optical activity of the product? (ii) Draw the energy profile for the reaction (iii) Write the structure of hte inermediate (iv) What is the effect of the doubling concentration of K on the rate of the products? (v) If aqueous K is replaced by alcoholic K. Write the structure of the products formed 33. Suggest a method for the following transformation involving minimum number of steps N 2 C Indicate the reagents/reaction conditions required at each step clearly. A dipeptide on hydrolysis gives two amino acids (X) and (Y). If the dipeptide is first treated with N 2 and then hydrolysis is carried out, (X) and lactic acid are obtained. (X) on heating gives 2, 5-diketopiperazine as shown below. Identify (X) and (Y), and write their sequence in the dipeptide. N 34. Identify the compounds A, B, C, D and E in the following reactions. N [A] 2 S 4 gs 4 C 6 5 C (i), PhC (ii) +, heat [B] N 2 N 2 /K heat [D] + [E] (i) 3 (ii) Zn/ 2 [C] 5

6 35. Why do the boiling points of the following compounds vary in order, 2 2Se 2S? Identify the products in the reaction of CCl 4 and SiCl 4 with water. Justify your answer. CEMISTRY 36. Write the steps involved in the production of pure elemental silicon from silica. Both the products A and B, in the following reactions, contain boron and nitrogen. Identify A and B. C65Cl LiAl4 4 3 heat TF 3N Cl 3BCl A B 37. Addition of potassium oxalate solution to a hot solution of potassium dichromate containing dilute sulfuric acid leads to effervescence and formation of potassium trisoxalatohromate (III). (i) Write the chemical formula of the chromium complex formed. (ii) Write the balanced chemical formula for the formation of the complex. (iii) Calculate the room temperature spin-only magnetic moment, in Bohr magnetons, of the complex. Write the structures of possible isomers of CoCl2 en Cl Draw the unit cell of CsCl lattice. Draw the (100) and (110) planes separately and indicate the positions of cesium and chloride ions. The hydration enthalpies of divalent metal ions of ten elements from calcium to zinc are plotted against their atomic numbers. Why do the hydration enthalpies of only three elements Ca, Mn and Zn fall on a straight line, whereas values for other metal ions deviate from this line grams of a protein was hydrolysed into amino acids, one of which is alanine. To this mixture, 0.1 gram of partially deutrated alanine, N C CD C, was added. After through mixing, some of 2 3 the alanine was separted and purified by crystallization. The crystalline alanine contains weight percent of D. ow many grams of alanine were originally present in 5 grams of protein? What is the role of ammoniacal buffer in the volumetric titration of zinc sulphate against EDTA, using Solochrome black (Eriochrome black T) indicator? Write the structure of Zn-EDTA anionic complex. 40. Calculate the p of a solution obtained by mixing ml of 0.20 M weak acid A (K a = 10 5 ) and ml of 0.20 M Na at room temperature. ne mole of a salt of type MX is dissolved in 1.00 Kg of water. The freezing point of the solution is 2.4ºC. Calculate the percent dissociation of the salt in water. 41. The rate constant of the reaction Cl N Cl N2 varies with temperature as: T K k cm s Determine the Arrhenius activation energy of the reaction, assuming that the frequency factor does not change in this temperature range. zone seems to be formed in the atmosphere through the photolysis of diatomic molecule: k 0 2 hv k1 2 3 k ; ; 2 Applying steady-state approximation, determine the rate law for the formation of ozone. Show that the formation of ozone follows first order kinetics when the concentration of 3 is extremely small. 6

7 CEMISTRY 42. The reaction N2 32 2N3 is carried out at 300 K by mixing N 2 and 2. The standard free energy of formation of N 3 is 16.4 kj/mol. After one hour of mixing, the partial pressures of N 2, 2 and N 3 are 50 bars, 2 bars and 200 bars, respectively. What is the reaction free energy at this stage of the reaction? Plot schematically the concentration dependence of molar conductivity of a strong electrolyte and a weak electrolyte in the same figure. The limiting ionic molar conductivities of K + and Cl are 73.5 and 76.5 Scm 2 mol 1, respectivley. If the molar conductivity of 0.1 M KCl solution is S cm 2 mol 1, calculate the Kohlrausch s constant for KCl solution. 43. The electronic wavefunction for hydrogen atom in the 2s state is given as r r 2 exp a 2a 0 0 Determine the most probable radial distance for the electron in this state and also the position of the node (in terms of a 0 ). Calculate the wavelength corresponding to the lowest energy excitation of an electron confined to a onedimensional box of length 1 nm. (Energy levels for a particle in-a-one-dimensional box are given by E n = n 2 h 2 /8ma 2 ). 44. Solve the differential equation y" 5y ' 6y 0 y 0 1 and y' 0 0. ere with the intial conditions y ' and y" refer to the first and the second derivatives, respectively, of y with respect to x. Verify your answer. For a particle with position r 2i ˆ 3j ˆ kˆ and momentum p ˆi 2j ˆ 2kˆ in m and kg.m.s 1, respectively, calculate the magnitude of the angular momentum L r p 7

JAM 2006 CHEMISTRY TEST PAPER

JAM 2006 CHEMISTRY TEST PAPER Useful Data RT 2.303 0.059 F = V at 298.15 K R = 8.3145 J.mol 1 K 1 F = 96500 C.mol 1 K W = 10 14 at 298.15 K me 31 = 9 10 kg K f = 1.8 C / m for water h 34 = 6.6 10 J.s ln