Practice Questions

Q47.An element has a face-centered cubic fcc structure with a cell edge of a. The distance between the centres of two nearest tetrahedral voids in the lattice is a 3 (1) (2) 2 2a (3) a (4) √2a

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

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.The reaction 2X →B is a zeroth order reaction. If the initial concentration of X is 0.2M, the half-life is 6 h. When the initial concentration of X is 0.5M, the time required to reach its final concentration of 0.2M will be (1) 9.0 h (2) 12.0 h (3) 18.0 h (4) 7.2 h

Q47.The standard electrode potential Eo and its temperature coefficient ( dTdE ) for a cell are 2 V and −5×10−4 V K−1 at 300 K, respectively. The reaction is Zn (s) + Cu2+ (aq) →Zn2+ (aq) + Cu (s). The standard reaction enthalpy (ΔrH−) at 300 K in mol−1 is [Use R = 8 J K−1 mol−1 and F =96,500 C mol−1] (1) −412.8 (2) 206.4 (3) −384.0 (4) 192.0

Q47.Liquids A and B form an ideal solution in the entire composition range. At 350K, the vapour pressure of pure A and pure B are 7 × 103 Pa and 12 × 103 Pa , respectively. The composition of the vapour in equilibrium with a solution containing 40 mole percent of A at this temperature is: (1) xA = 0.4; xB = 0.6 (2) xA = 0.76; xB = 0.24 (3) xA = 0.28; xB = 0.72 (4) xA = 0.37; xB = 0.63

Q47.For the cell Zn(s) Zn2+(aq)∥Mx+(aq) M(s), different half cells and their standard electrode potentials are given below: JEE Main 2019 (11 Jan Shift 1) JEE Main Previous Year Paper If E∘ = −0.76 V, which cathode will give a maximum value of E cell0 per electron transferred? Zn2+/Zn (1) Ag+/Ag (2) Fe3+/Fe2+ (3) Au3+/Au (4) Fe2+/Fe

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 given plots represent the variation of the concentration of a reactant R with time for two different reactions (i) and (ii) . The respective orders of the reaction are (i) (ii) (1) 1,1 (2) 0,1 (3) 1,0 (4) 0,2

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

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. 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.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.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.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

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 maximum possible denticities of a ligand given below towards a common transition and inner-transition metal ion, respectively, are: (1) 8 and 6 (2) 6 and 6 (3) 8 and 8 (4) 6 and 8 JEE Main 2019 (09 Apr Shift 2) JEE Main Previous Year Paper

Q49.For the reaction of H2 with I2, the rate constant is 2.5 × 10-4 dm3mol-1s-1 at 327oC and 1.0 dm3 mol-1s-1 at 527°C . The activation energy for the reaction, in kJ mol-1 is: R = 8.314 JK-1mol-1 (1) 166 (2) 59 (3) 72 (4) 150

Q49.The oxoacid of sulphur that does not contain bond between sulphur atom is: (1) H2S2O7 (2) H2S2O4 (3) H2S4O6 (4) H2S2O3

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