Electrochemistry PYQs Set 3 (PDF)

Set 3 of 13 · Questions 61-90 of 363

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Mere Teacher · Previous Year Questions JEE Main Chemistry · Electrochemistry · Set 3 (Q61-90)
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61. $For a closed circuit Daniell cell, which of the following plots is the accurate one at a given temperature?$ (1) (2) (3) (4) 62. $The standard electrode potential (M^{3 +} / M^{2 +}) for V, Cr, Mn & Co are -0.26 V, - 0,41 V, + 1.57 V and + 1.97 V, respectively. The metal ions which can liberate H_{2} from a dilute acid are$ (1) $V^{2 +} and M n^{2 +}$ (2) $Cr and CO$ (3) $V^{2 +} and C r^{2 +}$ (4) $M n^{2 +} and C o^{2 +}$ 63. $How many faradays of electricity are required to deposit 10 g of calcium from molten calcium chloride using inert electrodes? (molar mass of calcium = 40 g mol^{- 1})$ (1) $0.5 F$ (2) $1 F$ (3) $0.25 F$ (4) $2 F$ 64. $During the electrolysis of brine, by using inert electrodes,$ (1) $O_{2} liberates at anode$ (2) $H_{2} liberates at anode$ (3) $Na deposits on cathode$ (4) $Cl_{2} liberates at anode.$ 65. $The standard cell potential (E_{cell}^{⊖}) of a fuel cell based on the oxidation of methanol in air that has been used to power television relay station is measured as 1.21 V. The standard half cell reduction potential for O_{2} (E_{O_{2} / H_{2} O}^{\circ}) is 1.229 V. Choose the correct statement:$ (1) $Reactants are fed at one go to each electrode.$ (2) $Oxygen is formed at the anode.$ (3) $The standard half cell reduction potential for the reduction of CO_{2} (E_{CO_{2} / CH_{3} OH}^{\circ}) is 19 mV$ (4) $Reduction of methanol takes place at the cathode.$ 66. $The charge required for the reduction of 1 mole of MnO_{4}^{-} to MnO_{2} is$ (1) $1 F$ (2) $3 F$ (3) $5 F$ (4) $7 F$ 67. $The standard Gibbs energy (Δ G^{0}) for the following reaction is A (s) + B^{2 +} (aq) \to A^{2 +} (aq) + B (s), K_{c} = 10^{12} at 25^{\circ} C (K_{c} =) equilibrium constant)$ (1) $- 150 kJ$ (2) $- 96.80 kJ$ (3) $- 68.47 kJ$ (4) $- 100 kJ$ 68. $The number of Faradays required to completely deposit magnesium from 1 L of 0.1 M MgCl_{2} aq. solution is$ (1) $0.2$ (2) $2$ (3) $0.1$ (4) $0.4$ 69. $A 200 W, 100 V bulb is connected in series with an electrolytic cell. If an aqueous solution of an Sn -salt is electrolysed for 5 hrs, 11.1 g of Sn gets deposited. The chemical formula of the compound is ______(Given atomics weight of Sn is 118.7 g mol^{- 1}).$ (1) $SnO$ (2) $SnCl_{2}$ (3) $SnCl_{4}$ (4) $SnO_{2}$ 70. $A current of 19296 C is passed through an aqueous solution of copper sulphate using copper electrodes. What is the mass (in g) of copper deposited at the cathode? (Molar mass of (Cu = 63.5 g mol^{- 1})$ (1) $3.17$ (2) $1.58$ (3) $6.35$ (4) $0.79$ 71. $Calculate mass of a divalent metal produced at cathode by passing 5 amp current through its salt solution for 100 minute. (Molar mass of metal = x)$ (1) $\frac{15}{193} x$ (2) $\frac{193}{30} x$ (3) $\frac{30}{193} x$ (4) $\frac{193}{15} x$ 72. $The reaction; \frac{1}{2} H_{2 (g)} + AgCl_{(s)} \to H_{(aq)}^{+} + Cl_{(aq)}^{-} + Ag_{(s)} occurs in which of the following galvanic cell :$ (1) $Ag (AgCl_{(s)}) KCl_{(soln .)} (AgNO_{3 (aq .)}) Ag$ (2) $Pt (H_{2 (g)}) HCl_{(soln .)} (AgCl_{(s)}) Ag$ (3) $Pt (H_{2 (g)}) KCl_{(soln .)} (AgCl_{(s)}) Ag$ (4) $Pt (H_{2 (g)}) HCl_{(soln .)} (AgNO_{3 (aq)}) Ag$ 73. $Reduction potential of ions are given below: ClO_{4}^{-} IO_{4}^{-} BrO_{4}^{-} E^{\circ} = 1.19 V E^{\circ} = 1.65 V E^{\circ} = 1.74 V The correct order of their oxidising power is:$ (1) $ClO_{4}^{-} > IO_{4}^{-} > BrO_{4}^{-}$ (2) $BrO_{4}^{-} > IO_{4}^{-} > ClO_{4}^{-}$ (3) $BrO_{4}^{-} > ClO_{4}^{-} > IO_{4}^{-}$ (4) $IO_{4}^{-} > BrO_{4}^{-} > ClO_{4}^{-}$ 74. $The minimum voltage (in V) required to bring about the electrolysis of 1M copper (II) sulphate solution at 298 K is (Given E^{\circ} Cu^{2 +} / Cu = 0.34 V and (E^{\circ}_{H_{2} O / H^{+}} = - 1.23 V)$ (1) $+1.57$ (2) $+0.89$ (3) $-0.89$ (4) $-1.57$ 75. $How many grams of cobalt metal will be deposited when a solution ofcobalt (II) chloride is electrolyzed with a current of 10 amperes for 109 minutes (1 Faraday = 96, 500 C; Atomic mass of Co = 59 u)$ (1) $4.0$ (2) $20.0$ (3) $40.0$ (4) $0.66$ 76. $Which of the following electrolytic solutions has the least specific conductance?$ (1) $2 N$ (2) $0.002 N$ (3) $0.02 N$ (4) $0.2 N$ 77. $The molar conductivity of a 1.5 M solution of an electrolyte is found to be 138.9 S cm^{2} mol^{- 1} . The conductivity of this solution is$ (1) $1.325 S cm^{- 1}$ (2) $0.350 S cm^{- 1}$ (3) $0.208 S cm^{- 1}$ (4) $2.085 S cm^{- 1}$ 78. $The correct representation of Nernst equation for batscell reaction Cu_{(aq)}^{2 +} + e^{-} \to Cu_{(aq)}^{+} is$ (1) $E_{Cu^{+}, Cu^{2 +}}^{\circ} = E_{Cu^{+}, Cu^{2 +}} - \frac{0.0592}{2} log \frac{( Cu ^{+} )}{( Cu ^{2 +} )}$ (2) $E_{Cu^{+}, Cu^{2 +}} = E_{Cu^{+}, Cu^{2 +}}^{\circ} - \frac{0.0592}{1} log \frac{( Cu ^{+} )}{( Cu ^{2 +} )}$ (3) $E_{Cu^{+}, Cu^{2 +}}^{\circ} = E_{Cu^{+}, Cu^{2 +}}^{\circ} + \frac{0.0592}{2} log \frac{( Cu ^{+} )}{( Cu ^{2 +} )}$ (4) $none of the above$ 79. $Which one of the following graphs between molar conductivity (A_{m}) versus C is correct?$ (1) (2) (3) (4) 80. $O_{2} gas will be evolved as a product of electrolysis of: (A) an aqueous solution of AgNO3 using silver electrodes. (B) an aqueous solution of AgNO3 using platinum electrodes. (C) a dilute solution of H2SO4 using platinum electrodes. (D) a high concentration solution of H2SO4 using platinum electrodes. Choose the correct answer from the options given below:$ (1) $(A) and (C) only$ (2) $(B) and (C) only$ (3) $(A) and (D) only$ (4) $(B) and (D) only$ 81. $The standard emf of a galvanic cell involving 2 moles of electrons in its redox reaction is 0.59 V . The equilibrium constant for the redox reaction of the cell is$ (1) $10^{20}$ (2) $10^{5}$ (3) $10$ (4) $10^{10}$ 82. $For a Mg (Mg^{2 +} (aq)) (Ag^{+} (aq)) Ag the correct Nernst Equation is:$ (1) $E_{cell} = E_{cell}^{o} - \frac{RT}{2 F} ln \frac{( Ag ^{+} )}{( Mg ^{2 +} )}$ (2) $E_{cell} = E_{cell}^{o} + \frac{RT}{2 F} ln \frac{( Ag ^{+} ) ^{2}}{( Mg ^{2 +} )}$ (3) $E_{cell} = E_{cell}^{o} - \frac{RT}{2 F} ln \frac{( Ag ^{+} ) ^{2}}{( Mg ^{2 +} )}$ (4) $E_{cell} = E_{cell}^{o} - \frac{RT}{2 F} ln \frac{( Mg ^{2 +} )}{( Ag ^{+} )}$ 83. $On passing a current of 1.2 A through a solution of salt of 40 min, 0.96 g of copper was deposited. The equivalent weight of copper in g is$ (1) $21.2$ (2) $31.75$ (3) $63.5$ (4) $15.9$ 84. $The equilibrium constant of the reaction: A_{(s)} + 2 B_{(aq)}^{+} ⇌ A_{(aq)}^{2 +} + 2 B_{(s)}; E_{cell}^{o} = 0.0295 V is (\frac{2.303 RT}{F} = 0.059)$ (1) $10$ (2) $2 \times 10^{2}$ (3) $3 \times 10^{2}$ (4) $2 \times 10^{5}$ 85. $A solution contains F e^{2 +}, F e^{3 +} and I^{-} ions. This solution was treated with iodine at 3 5^{o} C . E^{o} for F e^{3 +} / F e^{2 +} i s + 0.77 V and E^{o} for I_{2} /2 I^{-} = 0.536 V. The favourable redox reaction is$ (1) $I_{2} will be reduced to I^{-}$ (2) $there will be no redox reaction$ (3) $I^{-} will be oxidised to I_{2}$ (4) $F e^{2 +} will be oxidised to F e^{3 +}$ 86. $108 g of silver (molar mass 108 g mo l^{- 1}) is deposited at cathode from AgN O_{3} (aq) solution by certain quantity of electricity. The volume (in L) of oxygen gas produced at 273 K and 1 bar pressure from water by the same quantity of electricity is\dots.$ 87. $What would be the electrode potential for the given half cell reaction at pH = 5 ? Given: 2 H_{2} O \to O_{2} + 4 H^{+} + 4 e^{-} E °_{red} = - 1.23 V (R = 8.314 J mo l^{- 1} K^{- 1}; Temp = 298 K; oxygen under std. pressure of 1 bar) Multiply your answer with - 100 .$ 88. $The mass of zinc produced by the electrolysis of zinc sulphate solution with a steady current of 0.015 A for 15 minutes is_________\times 10^{- 4} g . (Atomic mass of zinc = 65.4 amu)$ 89. $The potential for the given half cell at 298 K is (-) \dots \dots \dots \dots \times 10^{- 2} V 2 H^{+} (aq) + 2 e^{-} \to H_{2} (g) (H^{+}) = 1 M, P_{H_{2}} = 2 atm (Given: 2.303 RT / F = 0.06 V, log 2 = 0.3)$ 90. $For the reaction taking place in the cell: Pt(s)\| H_{2} (g)\| H^{+} (aq)\|\| A g^{+} (aq)\|Ag(s) E°_{C e l l} = +0.5332 V. The value of ∆_{f} G^{0} is________kJ m o l^{- 1} . (in nearest integer)$