IIT JAM Chemistry 2013
Previous Year Question Paper with Solution.

1.    The most polar compound among the following is:

    (a) SF4

    (b) BF3

    (c) XeF4

    (d) SO3

Ans.    a


    Correct option is (a)

2.    Which one of the following order of the carbonates is Correct for their decomposition temperature?

    (a) BaCO3 > CaCO3 > SrCO3 > MgCO3

    (b) BaCO3 > SrCO3 > CaCO3 > MgCO3

    (c) MgCO3 > CaCO3 > SrCO3 > BaCO3

    (d) MgCO3 > CaCO3 > BaCO3 > SrCO3

Ans.    b


    In case of polyatomic anion, Thermal stability of decomposition temperature is governed by covalent character


     BeCO3 < MgCO3 < CaCO3 < SrCO3 < BaCO3

    Correct option is (b)

3.    The Correct order of CO vibrational stretching frequency in the following complexes is

    (I) (PF3)3Mo(CO)3

    (II) (PCl3)3Mo(CO)3

    (III) {P(OMe)3}3Mo(CO)3

    (a) I < II < III

    (b) III < II < I

    (c) II < I < III

    (d) III < I < II

Ans.    2

Sol.    Since the attached to central metal cause the increase in the B.O. of CO, CO vibrational frequency increases. The order of is

    PF3 > PCl3 > P(OR)3

    Therefore, order of vibrational stretching frequency is {P(OMe3)3} MO(CO)3 < (PCl3)3MO(CO)3 < (PF3)3MO(CO)3.

    Correct option is (b)

4.    Among the following, the ligand that BEST stabilizes low oxidation state of tungsten (W) is

    (a) H2O

    (b) NH3

    (c) CO

    (d) F

Ans.    b

Sol.    Low oxidation state of W is stabilized by CO because of

    Correct option is (b)

5.    The function y = x exp (–x2) has a minimum at The second derivative of the function at the minimum is



    (c) 0


Ans.    a

Sol.     second derivative of the function.


    Correct option is (a)

6.    For a particular reaction at constant temperature, a plot of inverse of reactant concentration versus time is a straight line with a slope of 4.0 × 10–2 L mol–1 s–1. The time required (in seconds) for 1.0 M of reactant to decrease to 0.25 M is:

    (a) 18.8

    (b) 34.7

    (c) 75.0

    (d) 187.5

Ans.    c

Sol.    vs 't' graph gives straight line for a second order reaction



    Slope = k2 = 4 × 10–2 L mol–1 sec–1

    And    a = 1.0 M    and a – x = 0.25 M

    Therefore, (1), 4 × 10–2 t =

    Correct option is (c)

7.    For a physisorption process, which one of the following statements is NOT correct?

    (a) There are van der Waals interactions between the adsorbate and the adsorbent.

    (b) The process predominates at low temperature

    (c) The process cannot proceed beyond a monolayer

    (d) The process is reversible

Ans.    c

Sol.    Physisorption is a reversible process in which the adsorbate molecules are attached to the adsorbent surface by weak vander waals forces preferably at low temperature.

    Correct option is (c)

8.    The product of the following reaction is






Ans.    a


    Correct option is (a)

9.    The Correct order of stability of the following carbonium ions is


    (a) II > I > III

    (b) III > II > I

    (c) I > II > II

    (d) II > III > I

Ans.    d

Sol.    Carbocation at bridge head position is less stable because their rigid framework.



10.    Which one of the following statements is Correct?

    (a) Naturally occuring DNA has B-configuration.

    (b) Nucleic acids are derived from proteins.

    (c) Proteins store genetic information

    (d) Vitamins generally act as enzymes

Ans.    a

Sol.    Because nucleic acids are polymer whose monomer is nucleotides not protein. So, (b) not correct.

    Proteins are generally acts as enzyme but not vitamins. Proteins do not contain genetic information, its DNA which contain genetic information.

    Correct option is (a)

11.    The reaction of anhydrous FeCl2 with sodium-pentadienyl in ether gives an air-stable diamagnetic orange solid, which on oxidation gives an air-sensitive paramgnetic blue-green compound in solution. The blue-green compound is _____________



12.    CaO, VO and MnO have octahedral coordination of the metal ions in a rock-salt structure. The correct increasing order of their lattice enthalpies is __________


13.    The shape of the interhalide IF8 is __________


14.    The vapour pressures of solid and liquid chlorine are given by


    where Psolid and Pliq are the vapour pressures (in Torr) of solid and liquid chlorine near the triple point, respectively and T is the absolute temperature. The ratio of the slope of the solid-gas curve to the slope of the liquid gas curve at the triple point in the P-T diagram is________



15.    For unnormalized wave-function, the number of radial node(s) is __________

Sol.    Un normalized wave function

    Number of radial node.

    Radial node is n – – 1 for given function n = 3, l = 1


    Function is He+ because the part

    Function related to 3px orbitals.

16.    A hypothetical element (atomic weight = 300) crystallizes in a simple cubic lattice. For this crystal, the first order X-ray diffraction with wavelength of 5 Å appears at an angle of 30º. The density of the crystal is _____________g cm–3. [Avogadro number, NA = 6.02 × 1023]

Sol.    According to Bragg's equation


    And    for SCC, d = a = 5Å = 5 × 108 cm

    Now density will be given as



    For the above reaction if the equilibrium constant at 298 K is represented by 10x, then the value of X is _________

    [Given: The standard cell potential 0.06 V at 298 K]



18.    The rotational energy barrier between the most stable and the least stable conformations of 2, 3-dimethylbutane along C2–C3 bond is ___________kcal mol–1.

    [Given: The energies (kcal mol–1) for H/CH3 eclipsing = 1.8, CH3/CH3 eclipsing = 2.9 and CH3/CH3 gauche = 0.9]



19.    The number of peaks or signals in 1H NMR of N, N-dimethylformamide (DMF) at 25ºC is ______

Sol.    Distinguishable hydrogen are indicated by a and b here.

    at 25ºC two signals.


    Hence, correct answer is 3.


    Calixene is a polar hydrocarbon with a high dipole moment. The most stable dipolar canonical structure is _________


21.    A mixture of C3H8 and oxygen in 1L closed vessel has an internal pressure of 4 atm at 100ºC. When the mixture is ignited, the reaction produces CO2(g) and H2O(g) until all oxygen is consumed. After the reaction, pressure of the vessel is 4.2 atm at the same temperature. Calculate the weight of oxygen present before the reaction. [Gas constant, R = 0.082 L atm mol–1 K–1].




    weight of O2 = x × 32 = 0.032 × 32 = 1.024 gm

22.    The following reaction is carried out at 1 atm and 300 K


     for the above reaction is 550 kJ. Assuming ideal gas behaviour for H2 and O2, calculate the value of The value of gas constant, R = 0.082 L atm mol–1 K–1 = 8.314 mol–1 K–1.

    [Given: The volume of 1 mole of liquid water is 18 mL under the above reaction condition]


     = number of gaseous moles of product – number of gaseous moles of reactant



23.    At 298 K, calculate the solubility of metal sulfide, MS(s), in a saturated solution of H2S where the concentration of H2S and pH are maintained at 0.1 M and 3.0, respectively

    Given at 298 K,




24.    For each of the following metallo-proteins identify the metal-ion at the active-site and the function of the proteins:

    deoxy-hemoglobin, deoxy-myoglobin, oxy-hemocyanin, cytochrome-C and carbonic anhydrase.

Sol.    Deoxy-hemoglobin


25.    A solution containing 250 ppm of CuSO4 · 5H2O (formula weight = 250) has an absorbance of 0.1 measured in 1 cm cell at 600 nm. Calculate the molar absorptivity of CuSO4 · 5H2O in L M–1 cm–1. When 25 mL of Na2EDTA (aq) solution is titrated against Na2EDTA (aq) solution, it consumes at 50 mL of Na2EDTA (aq) solution. Calculate the concentration of Na2EDTA (aq) solution in moles L–1.

Sol.    C = 250 ppm = 10–3 mol ltr.

    A = 0.1, x = 1 cm


26.    Assume the complex [NI(PPh3)2(SCN)2] is paramagnetic. The analogous complex of Pd(II) is diamagnetic. Draw all the probable isomers for both the complexes considering SCN is an ambidentate ligand.




    Chemical transformation involved in above chemical reaction can be illustrated as



28.    Write the structures of F to J in the following reaction scheme:


    [DiBAL-H = diisobutylaluminium hydride]

Sol.    Chemical transformation involved in above chemical reaction can be illustrated as



29.    Propose a mechanism for the following reaction. Show stepwise correct reactive intermediates


Sol.    Chemical transformation involved in above chemical reaction can be illustrated as



30.    Complete the following reaction sequence and write structures of K to O.


    Chemical transformation involved in above chemical reaction can be illustrated as

Sol.    Chemical transformation involved in above chemical reaction can be illustrated as