Practice Questions

Q38.The equilibrium constant (Kc) for the reaction N2(g) + O2( g) →2NO(g) at temperature T is 4 × 10−4 . The value of Kc for the reaction, NO(g) →1/2 N2(g) + 1/2 O2(g) at the same temperature is : (1) 0.02 (2) 2.5 × 102 (3) 4 × 10−4 (4) 50.0

Q38.One mole of O2( g) and two moles of SO2( g) were heated in a closed vessel of one-litre capacity at 1098 K. At equilibrium 1.6 moles of SO3( g) were found. The equilibrium constant Kc of the reaction would be (1) 30 (2) 40 (3) 80 (4) 60

Q39.The electron affinity of chlorine is 3.7eV.1 gram of chlorine is completely converted to Cl− ion in a gaseous state. (1eV = 23.06kcalmol−1). Energy released in the process is (1) 4.8kcal (2) 7.2kcal (3) 8.2kcal (4) 2.4kcal

Q39.The difference between the reaction enthalpy change (ΔrH) and reaction internal energy change (ΔrU) for the reaction: 2C6H6(l) + 15O2( g) ⟶ at 300 K is (R = 8.314 J mol−1 K−1) JEE Main 2012 (12 May Online) JEE Main Previous Year Paper (1) 0 J mol−1 (2) 2490 J mol−1 (3) −2490 J mol−1 (4) −7482 J mol−1 Q40. 8 mol of AB3( g) are introduced into a 1.0dm3 vessel. If it dissociates as 2AB3(g) ⇌A2(g) + 3B2(g). At equilibrium, 2 mol of A2 are found to be present. The equilibrium constant of this reaction is (1) 2 (2) 3 (3) 27 (4) 36

Q39.The pH of a 0.1 molar solution of the acid HQ is 3 . The value of the ionization constant, Ka of this acid is : (1) 3 × 10−1 (2) 1 × 10−3 (3) 1 × 10−5 (4) 1 × 10−7

Q39.An open vessel at 300 K is heated till 2/5th of the air in it is expelled. Assuming that the volume of the vessel remains constant, the temperature to which the vessel is heated, is (1) 1500 K (2) 400 K (3) 500 K (4) 750 K

Q39.The solubility of PbI2 at 25∘C is 0.7 g L−1 . The solubility product of PbI2 at this temperature is (molar mass of PbI2 = 461.2 g mol−1 ) (1) 1.40 × 10−9 (2) 0.14 × 10−9 (3) 140 × 10−9 (4) 14.0 × 10−9

Q40.The solubility (in mol L−1 ) of AgCl (Ksp = 1.0 × 10−10) in a 0.1MKCl solution will be (1) 1.0 × 10−9 (2) 1.0 × 10−10 (3) 1.0 × 10−5 (4) 1.0 × 10−11

Q40.Very pure hydrogen (99.9%) can be made by which of the following processes? (1) Reaction of methane with steam (2) Mixing natural hydrocarbons of high molecular weight (3) Electrolysis of water (4) Reaction of salt like hydrides with water

Q40.Fire extinguishers contain H2SO4 and which one of the following? JEE Main 2012 (26 May Online) JEE Main Previous Year Paper (1) NaHCO3 and Na2CO3 (2) Na2CO3 (3) NaHCO3 (4) CaCO23

Q40.The enthalpy of neutralisation of NH4OH with HCl is −51.46 kJ mol−1 and the enthalpy of neutralisation of NaOH with HCl is −55.90 kJ mol−1 . The enthalpy of ionisation of NH4OH is (1) −107.36 kJ mol−1 (2) −4.44 kJ mol−1 (3) +107.36 kJ mol−1 (4) +4.44 kJ mol−1

Q41.Which of the oxide groups among the following cannot be reduced by carbon? (1) Cu2O, SnO2 (2) CaO, K2O (3) PbO, Fe2O4 (4) Fe2O3, ZnO

Q41.The value of Kp for the equilibrium reaction N2O4(g) ⇌2NO2(g) is 2 . The percentage dissociation of N2O4(g) at a pressure of 0.5 atm is (1) 25 (2) 88 (3) 50 (4) 71

Q41.Given (i) HCN(aq) + H2O(b) ⇌H3O+(aq) + CN−(aq) Ka = 6.2 × 10−10 (ii) CN−(aq) + H2O(l) ⇌HCN(aq) + OH−(aq) Kb = 1.6 × 10−5 . These equilibria show the following order of the relative base strength, (1) OH−> H2O > CN− (2) OH−> CN−> H2O (3) H2O > CN−> OH (4) CN−> H2O > OH−

Q41.Which of the following on thermal decomposition yields a basic as well as an acidic oxide ? (1) NaNO3 (2) KClO3 (3) CaCO3 (4) NH4NO3

Q41. In the following compounds: the order of basicity is as follows (1) IV > III > II > I (2) III > I > II > IV (3) II > III > I > IV (4) I > III > II > IV

Q42.Which of the following cannot be represented by resonance structures? (1) Dimethyl ether (2) Nitrate anion (3) Carboxylate anion (4) Toluene

Q42.If Ksp of CaF2 at 25∘C is 1.7 × 10−10 , the combination amongst the following which gives a precipitate of CaF2 is (1) 1 × 10−2MCa2+ and 1 × 10−3MF− (2) 1 × 10−4MCa2+ and 1 × 10−4MF− (3) 1 × 10−2MCa2+ and 1 × 10−5MF− (4) 1 × 10−3MCa2+ and 1 × 10−5MF−

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

Q42.Ortho-Nitrophenol is less soluble in water than p− and m− Nitrophenols because : JEE Main 2012 (Offline) JEE Main Previous Year Paper (1) o−Nitrophenol is more volatile in steam than (2) o−Nitrophenol shows Intramolecular H− those of m− and p− isomers bonding (3) o− Nitrophenol shows Intermolecular H− (4) Melting point of o−Nitrophenol is lower than bonding those of m− and p− isomers. Q43. 2− Hexyne gives trans −2−Hexene on treatment with : (1) Pt/H2 (2) Li/NH3 (3) Pd/BaSO4 (4) LiAlH4

Q42.Maleic acid and fumaric acids are (1) Chain isomers (2) Functional isomers (3) Tautomers (4) Geometrical isomers

Q43.Copper wire test for halogens is known as (1) Duma's Test (2) Beilstein's Test (3) Liebig's Test (4) Lassigne's Test

Q43.Which of the following compounds are antiaromatic (1) (I) and (V) (2) (II) and (V) (3) (I) and (IV) (4) (V) and (VI)

Q43.A metal M on heating in nitrogen gas gives Y . Y on treatment with H2O gives a colourless gas which when passed through CuSO4 solution gives a blue colour. Y is (1) NH3 (2) Mg(NO3)2 (3) Mg3 N2 (4) MgO

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