Practice Questions

Q34.In which of the following ionization processes the bond energy has increased and also the magnetic behaviour has changed from paramagnetic to diamagnetic ? (1) NO →NO+ (2) N2 →N+2 (3) C2 →C+2 (4) O2 →O+2 JEE Main 2013 (09 Apr Online) JEE Main Previous Year Paper

Q38.The internuclear distances in O −O bonds for O+2 , O2, O−2 and O2−2 respectively are : (1) 1.30 Å, 1.49 Å, 1.12 Å, 1.21 Å (2) 1.49 Å, 1.21 Å, 1.12 Å, 1.30 Å (3) 1.21 Å, 1.12 Å, 1.49 Å, 1.30 Å (4) 1.12 Å, 1.21 Å, 1.30 Å, 1.49 Å

Q38.Which one of the following arrangements represents the correct order of solubilities of sparingly soluble salts Hg2Cl2, Cr2(SO4)3 , BaSO4 and CrCl3 respectively? (1) BaSO4 > Hg2Cl2 > Cr2(SO4)3 > CrCl3 (2) BaSO4 > Hg2Cl2 > CrCl3 > Cr2(SO4)3 (3) BaSO4 > CrCl3 > Hg2Cl2 > Cr2(SO4)3 (4) Hg2Cl2 > BaSO4 > CrCl3 > Cr2(SO4)3

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

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

Q51.The magnetic moment of the complex anion [Cr(NO) (NH3)(CN)4]2− is : (1) 5.91BM (2) 3.87BM (3) 1.73BM (4) 2.82BM

Q52.Which of the following is diamagnetic ? (1) [Fe(CN)6]3− (2) [Co(ox)3]3− (3) [FeF6]3− (4) [CoF6]3−

Q53.Which of the following arrangements does not represent the correct order of the property stated against it? (1) Co3+ < Fe3+ < Cr3+ < Sc3+ :​ Stability in aqueous (2) Sc < Ti < Cr < Mn :​ Number of oxidation states solution (3) V2+< Cr2+ < Mn2+ < Fe2+:​ Paramagnetic (4) Ni2+ < Co2+ < Fe2+ < Mn2+ :​ Ionic size behaviour

Q57.An ether (A), C5H12O, when heated with excess of hot concentrated HI produced two alkyl halides which when treated with NaOH yielded compounds (B) and (C). Oxidation of (B) and (C) gave a propanone and an ethanoic acid respectively. The IUPAC name of the ether (A) is : (1) 2−ethoxypropane (2) ethoxypropane (3) methoxybutane (4) 2−methoxybutane

Q57.Compound (A), C8H9 Cl, gives a white precipitate when warmed with alcoholic AgNO3 . Oxidation of (A) gives an acid (B), C8H6O4 . (B) easily forms anhydride on heating. Identify the compound (A). JEE Main 2013 (07 Apr) JEE Main Previous Year Paper (1) (2) ​ ​ (3) (4) ​ ​

Q34.In which of the following arrangements, the sequence is not strictly according to the property written against it? (1) CO2 < SiO2 < SnO2 < PbO2 : increasing (2) NH3 < PH3 < AsH3 < SbH3 : increasing basic oxidising power strength (3) HF < HCl < HBr < HI : increasing acid (4) B < C < O < N : increasing first ionisation strength enthalpy.

Q42. In the following balanced reaction, values of X, Y and Z respectively are (1) 2,5,16 (2) 8, 2, 5 (3) 5, 2, 16 (4) 5, 8, 4

Q43. The order of basicity of the compounds is (1) IV > I > III > II (2) I > III > II > IV (3) III > I > IV > II (4) II > I > III > IV JEE Main 2012 (19 May Online) JEE Main Previous Year Paper

Q48.A solution containing 0.85 g of ZnCl2 in 125.0 g of water freezes at −0.23∘C. The apparent degree of dissociation of the salt is (Kf for water = 1.86 K kg mol−1 , atomic mass: Zn = 65.3 and Cl = 35.5) (1) 1.36% (2) 73.5% (3) 7.35% (4) 2.47%

Q49.A battery is constructed of Cr and Na2Cr2O7 . The unbalanced chemical equation when such a battery discharges is following: Na2Cr2O7 + Cr + H+ →Cr3+ + H2O + Na+ If one Faraday of electricity is passed through the battery during the charging, the number of moles of Cr3+ removed from the solution is (1) 4 (2) 1 3 3 (3) 3 (4) 2 3 3

Q52.The number of S −S bonds in SO3, S2O2−3 S2O2−6 and S2O2−8 respectively are (1) 1, 0, 0, 1 (2) 1,0,1,0 (3) 0, 1, 1, 0 (4) 0, 1, 0, 1

Q54.Which branched chain isomer of the hydrocarbon with molecular mass 72 u gives only one isomer of mono substituted alky halide? (1) Tertiary butyl chloride (2) Neopentane (3) Isohexane (4) Neohexane

Q55.The complex ion [Pt (NO2)(Py) (NH3) (NH2OH)]+ will give (1) 2 isomers (Geometrical) (2) 3 isomers (Geometrical) (3) 6 isomers (Geometrical) (4) 4 isomers (Geometrical)

Q39.The entropy change involved in the isothermal reversible expansion of 2 moles of an ideal gas from a volume of 10dm3 to a volume of 100dm3 at 27∘C is : (1) 35.8 J mol−1 K−1 (2) 32.3 J mol−1 K−1 (3) 42.3 J mol−1 K−1 (4) 38.3 J mol−1 K−1

Q51.Consider the reaction : Cl2(aq) + H2 S(aq) →S(s) + 2H+(aq) + 2Cl−(aq) The rate equation for this reaction is rate = k [Cl2] [H2 S] Which of these mechanisms is/are consistent with this rate equation? (A) Cl2 + H2 →H+ + Cl−+ Cl+ + HS− (slow) Cl+ + HS−→H+ + Cl−+ S (fast) (B) H2 S ⇔H+ + HS− (fast equilibrium) Cl2 + HS−→2Cl−+ H+ + S (slow) (1) B only (2) Both A and B (3) Neither A nor B (4) A only

Q38.The bond dissociation energy of B −F in BF3 is 646 kJ mol −1 whereas that of C −F in CF4 is 515 kJ mol −1 . The correct reason for higher B-F bond dissociation energy as compared to that of C - F is : (1) smaller size of B-atom as compared to that of C- (2) stronger σ bond between B and F in BF3 as atom compared to that between C and F in CF4 (3) significant pπ −pπ interaction between B and F (4) lower degree of pπ −pπ interaction between B in BF3 whereas there is no possibility of such and F in BF3 than that between C and F in CF4 . interaction between C and F in CF4 . –––

Q50.Which one of the following reactions of Xenon compounds is not feasible ? (1) XeO3 + 6HF →Xe6 + 3H2O (2) 3Xe4 + 6H2O →2Xe + XeO3 + 12HF + 1.5O2 (3) 2XeF2 + 2H2O →2Xe + 4HF + O2 (4) XeF6 + RbF →Rb (XeF7]

Q71.Identify the incorrect statement among the following (1) Ozone reacts with SO2 to give SO3 (2) Silicon reacts with NaOH(aq) in the presence of air to give Na2SiO3 and H2O (3) Cl2 reacts with excess of NH3 to give N2 and (4) Br2 reacts with hot and strong NaOH solution to HCl give NaBr, NaBrO4 and H2O

Q89.A reaction was found to be second order with respect to the concentration of carbon monoxide. If the concentration of carbon monoxide is doubled, with everything else kept the same, the rate of reaction will (1) remain unchanged (2) triple (3) increase by a factor of 4 (4) double