Practice Questions

Q42.Arrange in the correct order of stability (decreasing order) for the following molecules: (I) (II) (III) (IV) (1) (I) > (II) > (III) > (IV) (2) (IV) > (III) > (II) ≈ (I) (3) (I) > (II) ≈ (III) > (IV) (4) (III) > (I) ≈ (II) > (IV)

Q42.Given that: (i) ΔfH∘ of N2O is 82 kJ mol−1 (ii) Bond energies of N ≡N, N = N, O = O and N = O are 946, 418, 498 and 607 kJ mol−1 respectively, The resonance energy of N2O is : (1) −88 kJ (2) −66 kJ (3) −62 kJ (4) −44 kJ

Q42.Monocarboxylic acids are functional isomers of: (1) Ethers (2) Amines (3) Esters (4) Alcohols

Q43.Which of the following compounds is not expected to show Lassaignes' test for nitrogen ? (1) Propanenitrile (2) Hydroxylamine hydrochloride (3) Nitromethane (4) Ethanamine

Q43.Consider the following reaction: x MnO−4 + y C2O2−4 + zH+ ⟶x Mn2+ + 2y CO2 + 2z H2O The values of x, y and z in the reaction are, respectively: (1) 2, 5 and 16 (2) 5, 2 and 8 (3) 5, 2 and 16 (4) 2, 5 and 8

Q43.The ratio Kp for the reaction CO(g) + 12 O2(g) ⇌CO2(g) is: Kc (1) 1 (2) (RT)1/2 √RT (3) RT (4) 1

Q43.A major component of Borsch reagent is obtained by reacting hydrazine hydrate with which of the following ? JEE Main 2013 (22 Apr Online) JEE Main Previous Year Paper (1) (2) (3) (4)

Q43.In a face centred cubic lattice, atoms of A form the corner points and atoms of B form the face centred points. If two atoms of A are missing from the corner points, the formula of the ionic compound is : (1) AB3 (2) AB4 (3) A2 B5 (4) AB2

Q44.Clemmensen reduction of a ketone is carried out in the presence of : (1) LiAlH4 (2) Zn −Hg with HCl (3) Glycol with KOH (4) H2 with Pt as catalyst

Q44.Vapour pressure of pure benzene is 119 torr and that of toluene is 37.0 torr at the same temperature. Mole fraction of toluene in vapour phase which is in equilibrium with a solution of benzene and toluene having a mole fraction of toluene 0.50, will be : (1) 0.137 (2) 0.237 (3) 0.435 (4) 0.205

Q44.A solution of (−)1 −chloro −1 −phenylethane in toluene racemises slowly in the presence of a small amount of SbCl5, due to the formation of : (1) Carbocation (2) Free radical (3) Carbanion (4) Carbene JEE Main 2013 (07 Apr) JEE Main Previous Year Paper

Q44.What would be the pH of a solution obtained by mixing 5 g of acetic acid and 7.5 g of sodium acetate and making the volume equal to 500 mL ? (Ka = 1.75 × 10−5, pKa = 4.76) (1) pH = 4.70 (2) pH < 4.70 (3) pH of solution will be equal to pH of acetic acid (4) 4.76 < pH < 5.0

Q44.The addition of HI in the presence of peroxide catalyst does not follow anti-Markovnikov's rule because : (1) HI is a strong reducing agent. (2) H −I bond is too strong to be broken homolytically. (3) I atom combines with H atom to give back HI. (4) Iodine atom is not reactive enough to add across a double bond.

Q45.Which of the following would not give 2-phenylbutane as the major product in a Friedel-Crafts alkylation reaction ? (1) 1-butene +HF (2) 2-butanol +H2SO4 (3) Butanoyl chloride +AlCl3 then Zn, HCl (4) Butyl choloride +AlCl3

Q45.Given : Eo1 1.36 V, Eo = −0.74 V 2 Cl2/Cl−= Cr3+/Cr Eo = 1.33 V, Eo = 1.51 V Cr2O2−7 /Cr3+ MnO−4 /Mn2+ The correct order of reducing power of the species (Cr, Cr3+, Mn2+ and Cl−)will be: (1) Mn2+ < Cl−< Cr3+ < Cr (2) Mn2+ < Cl3+ < Cl−< Cr (3) Cr3+ < Cl−< Mn2+ < Cr (4) Cr3+ < Cl−< Cr < Mn2+

Q45.Which one of the following arrangements represents the correct order of the proton affinity of the given species : (1) I−< F−< HS−< NH−2 (2) HS−< NH−2 < F−< I− (3) F−< I−< NH−2 < HS− (4) NH−2 < HS−< I−< F−

Q45.Arrange the following compounds in order of decreasing acidity : (1) III > I > II > IV (2) IV > III > I > II (3) II > IV > I > III (4) I > II > III > IV

Q45.An element having an atomic radius of 0.14 nm crystallizes in an fcc unit cell. What is the length of a side of the cell ? (1) 0.56 nm (2) 0.24 nm (3) 0.96 nm (4) 0.4 nm Q46. 12 g of a nonvolatile solute dissolved in 108 g of water produces the relative lowering of vapour pressure of 0.1. The molecular mass of the solute is : (1) 80 (2) 60 (3) 20 (4) 40

Q46. Given In the above compounds correct order of reactivity in electrophilic substitution reactions will be: (1) B > A > C > D (2) D > C > B > A (3) A > B > C > D (4) B > C > A > D

Q46.Which one of the following statements about packing in solids is incorrect ? (1) Coordination number in bcc mode of packing is 8 (2) Coordination number in hep mode of packing is . 12 . (3) Void space in hcp mode of packing is 32%. (4) Void space in ccp mode of packing is 26%.

Q46.The order of stability of the following carbocations: (1) I > II > III (2) III > I > II (3) III > II > I (4) II > III > I

Q46.The rate constant of a zero order reaction is 2.0× 10−2 mol L−1 s−1 . If the concentration of the reactant after 25 seconds is 0.5M. What is the initial concentration? (1) 0.5M (2) 1.25M (3) 12.5M (4) 1.0M

Q47.Copper crystallises in fcc with a unit length of 361 pm . What is the radius of copper atom ? (1) 157 pm (2) 128 pm (3) 108 pm (4) 181 pm

Q47.The gas leaked from a storage tank of the Union Carbide plant in Bhopal gas tragedy was : (1) Ammonia (2) Phosgene (3) Methyl isocyanate (4) Methylamine

Q47.Smoke is an example of: (1) Solid dispersed in solid (2) Gas dispersed in liquid (3) Solid dispersed in gas (4) Gas dispersed in solid