Practice Questions

Q47.The decreasing order of electrical conductivity of the following aqueous solutions is: (A) 0.1 M Formic acid, JEE Main 2019 (12 Apr Shift 2) JEE Main Previous Year Paper (B) 0.1 M Acetic acid, (C) 0.1 M Benzoic acid. (1) (A) > (B) > (C) (2) (A) > (C) > (B) (3) (C) > (B) > (A) (4) (C) > (A) > (B)

Q47.The vapour pressures of pure liquids A and Bare 400 and 600 mm Hg respectively at 298 K . On mixing the two liquids, the sum of their volumes is equal to the volume of the final mixture. The mole fraction of liquid B is 0.5 in the mixture. The vapour pressure of the final solution, the mole fractions of components A and B in the vapour phase, respectively are (1) 500 mm Hg, 0.5, 0.5 (2) 450 mm Hg, 0.4, 0.6 (3) 450 mm Hg, 0.5, 0.5 (4) 500 mm Hg, 0.4, 0.6

Q47.For a reaction scheme A → k1 B → k2 C, if the net rate of formation of B is set to be zero then the concentration of B is given by: (1) k1 + k2 [A] (2) k1k2 [A] (3) k1 (4) k1 - k2 [A] [A] k2

Q47.For a reaction, consider the plot of ln k versus 1/T given in the figure. If the rate constant of this reaction at 400 K is 10−5s−1 , then the rate constant at 500 K is: JEE Main 2019 (12 Jan Shift 2) JEE Main Previous Year Paper (1) 10−4s−1 (2) 10−6s−1 (3) 2 x 10−4s−1 (4) 4 x 10−4s−1

Q48. NO2 required for a reaction is produced by the decomposition of N2O5 in CCl4 as per the equation, 2N2O5(g) →4NO2(g) + O2(g). The initial concentration of N2O5 is 3.00 mol L−1 and it is 2.75 mol L−1 after 30 minutes. The rate of formation of NO2 is: (1) 1.667 × 10−2 mol L−1 min−1 (2) 8.333 × 10−3 mol L−1min−1 (3) 4.167 × 10−3 mol L−1min−1 (4) 2.083 × 10−3 mol L−1 min−1

Q48.Match the refining methods (Column I) with metals (Column II). Column I Column II (Refining methods) (Metals) (I) Liquation (a) Zr (II) Zone Refining (b) Ni (III) Mond Process (c) Sn (IV) Van Arkel Method (d) Ga (1) (I) −(b); (II) −(c); (III) −(d); (IV) −(a) (2) (I) −(b); (II) −(d); (III) −(a); (IV) −(c) (3) (I) −(c); (II) −(d); (III) −(b); (IV) −(a) (4) (I) −(c); (II) −(a); (III) −(b); (IV) −(d)

Q48.Among the colloids cheese (C), milk (M) and smoke (S), the correct combination of the dispersed phase and dispersion medium, respectively is : (1) C : liquid in solid; M : liquid in solid; S : solid in (2) C : liquid in solid; M : liquid in liquid; S : solid gas in gas (3) C : solid in liquid; M : liquid in liquid; S : gas in (4) C : solid in liquid; M : solid in liquid; S : solid in solid gas

Q48.The maximum number of possible oxidation states of actinoids are shown by: (1) nobelium (No) and lawrencium (Lr) (2) berkelium (Bk) and californium (Cf) (3) actinium (Ac) and thorium (Th) (4) neptunium (Np) and plutonium (Pu)

Q48.Consider the following reduction processes: Zn2+ + 2e−→Zn(s); Eo = −0 .76 V Ca2+ + 2e−→Ca(s); Eo = −2 .87 V JEE Main 2019 (10 Jan Shift 1) JEE Main Previous Year Paper Mg2+ + 2e−→Mg(s); Eo = −2 .36 V Ni2+ + 2e−→Ni(s); Eo = −0 .25 V The reducing power of the metals increases in the order: (1) Ca < Mg < Zn < Ni (2) Zn < Mg < Ni < Ca (3) Ni < Zn < Mg < Ca (4) Ca < Zn < Ni < Mg

Q48.The anodic half-cell of lead-acid battery is recharged using electricity of 0 .05 Faraday. The amount of PbSO4 electrolyzed in g during the process is: (Molar mass of PbSO4 = 303g mol-1) (1) 22.8 (2) 15.2 (3) 11.4 (4) 7.6

Q48.The Mond process is used for the: (1) Purification of Zr and Ti (2) Purification of Ni (3) Extraction of Zn (4) Extraction of Mo

Q48.The mole fraction of a solvent in aqueous solution of a solute is 0.8 . The molality (in mol kg-1 ) of the aqueous solution is: (1) 13.88 × 10-3 (2) 13.88 × 10-1 (3) 13.88 (4) 13.88 × 10-2

Q48.Among the following reactions of hydrogen with halogens, the one that requires a catalyst is: (1) H2 + Cl2 →2 HCl (2) H2 + I2 →2 HI (3) H2 + F2 →2 HF (4) H2 + Br2 →2 HBr

Q48.Decomposition of X exhibits a rate constant of 0 .05 μg/ year. How many years are required for the decomposition of 5 μg of X into 2 .5 μg? (1) 20 (2) 4 0 (3) 25 (4) 50

Q48.Among the following, the false statement is: (1) Latex is a colloidal solution of rubber particles (2) Tyndall effect can be used to distinguish between which are positively charged a colloidal solution and a true solution. (3) It is possible to cause artificial rain by throwing (4) Lyophilic sols can be coagulated by adding an electrified sand carrying charge opposite to the electrolyte. one on clouds from an aeroplane.

Q48.For the reaction 2A + B →C , the values of initial rate at different reactant concentrations are given in the table below. The rate law for the reactions is: [A] (mol L-1 ) [B] (mol L-1 ) Initial Rate (mol L-1s-1 ) 0.05 0.05 0.045 0.10 0.05 0.090 0.20 0.10 0.72 (1) Rate = k[A]2[B] (2) Rate = k[A]2[B]2 (3) Rate = k[A][B] (4) Rate = k[A][B]2

Q48.Which one of the following graphs between molar conductivity Λm versus √C is correct? (1) (2) (3) (4)

Q48.The aerosol is a kind of colloid in which (1) solid is dispersed in gas. (2) liquid is dispersed in water. (3) gas is dispersed in solid. (4) gas is dispersed in liquid.

Q48.The correct statement regarding the given Ellingham diagram is: (1) At 1400oC, Al can be used for the extraction of (2) At 500oC, coke can be used for the extraction of Zn from ZnO . Zn from ZnO (3) At 800oC, Cu can be used for the extraction of (4) Coke cannot be used for the extraction of Cu Zn from ZnO from Cu2O

Q48.If a reaction follows the Arrhenius equation, the plot ln k vs (RT)1 gives straight line with a gradient (−y) unit. The energy required to activate the reactant is: (1) y/R unit (2) y unit (3) yR unit (4) −y unit

Q49.Adsorption of a gas follows Freundlich adsorption isotherm. x is the mass of the gas adsorbed on mass m of the adsorbent. The plot of log x vs logp is shown in the given graph. x is proportional to, m m (1) p3 (2) p2 (3) p2 / 3 (4) p3 / 2

Q49.The following results were obtained during kinetic studies of the reaction. 2A + B → product Experiment A in mol L-1 B in mol L-1 Initial rate of reaction in mol L-1 min -1 I 0 . 10 0 . 20 6.93 × 10-3 II 0 . 10 0 . 25 6.93 × 10-3 III 0 . 20 0 . 30 1.386 × 10-2 The time (in minutes) required to consume half of A is (1) 100 (2) 10 (3) 5 (4) 1

Q49.In the following reaction; xA →yB dA dB log10⁡- dt = log10⁡- dt + 0.3010 ‘A’ and ‘B’ respectively can be: (1) C2H4 and C4H8 (2) C2H2 and C6H6 (3) n-Butane and Iso-butane (4) N2O4 and NO2

Q49.The ion that has sp3d2 hybridization for the central atom is: (1) BrF2 - (2) ICl4 - (3) IF6 - (4) ICl2 -

Q49.Good reducing nature of H3PO2 is attributed to the presence of: (1) One P −H bond (2) Two P −OH bonds (3) Two P −H bond (4) One P −OH bond