Electrochemistry PYQs Set 3 (PDF)

Set 3 of 10 · Questions 61-90 of 293

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Mere Teacher · Previous Year Questions NEET Chemistry · Electrochemistry · Set 3 (Q61-90)
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61. $The number of Faradays required to completely deposit magnesium from 1 L of 0.1 M MgCl_{2} aq. solution is$ (1) $0.2$ (2) $2$ (3) $0.1$ (4) $0.4$ 62. $A 200 W, 100 V bulb is connected in series with an electrolytic cell. If an aqueous solution of an Sn -salt is electrolysed for 5 hrs, 11.1 g of Sn gets deposited. The chemical formula of the compound is ______(Given atomics weight of Sn is 118.7 g mol^{- 1}).$ (1) $SnO$ (2) $SnCl_{2}$ (3) $SnCl_{4}$ (4) $SnO_{2}$ 63. $A current of 19296 C is passed through an aqueous solution of copper sulphate using copper electrodes. What is the mass (in g) of copper deposited at the cathode? (Molar mass of (Cu = 63.5 g mol^{- 1})$ (1) $3.17$ (2) $1.58$ (3) $6.35$ (4) $0.79$ 64. $Calculate mass of a divalent metal produced at cathode by passing 5 amp current through its salt solution for 100 minute. (Molar mass of metal = x)$ (1) $\frac{15}{193} x$ (2) $\frac{193}{30} x$ (3) $\frac{30}{193} x$ (4) $\frac{193}{15} x$ 65. $The reaction; \frac{1}{2} H_{2 (g)} + AgCl_{(s)} \to H_{(aq)}^{+} + Cl_{(aq)}^{-} + Ag_{(s)} occurs in which of the following galvanic cell :$ (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) $Pt (H_{2 (g)}) HCl_{(soln .)} (AgNO_{3 (aq)}) Ag$ 66. $Reduction potential of ions are given below: ClO_{4}^{-} IO_{4}^{-} BrO_{4}^{-} E^{\circ} = 1.19 V E^{\circ} = 1.65 V E^{\circ} = 1.74 V The correct order of their oxidising power is:$ (1) $ClO_{4}^{-} > IO_{4}^{-} > BrO_{4}^{-}$ (2) $BrO_{4}^{-} > IO_{4}^{-} > ClO_{4}^{-}$ (3) $BrO_{4}^{-} > ClO_{4}^{-} > IO_{4}^{-}$ (4) $IO_{4}^{-} > BrO_{4}^{-} > ClO_{4}^{-}$ 67. $The minimum voltage (in V) required to bring about the electrolysis of 1M copper (II) sulphate solution at 298 K is (Given E^{\circ} Cu^{2 +} / Cu = 0.34 V and (E^{\circ}_{H_{2} O / H^{+}} = - 1.23 V)$ (1) $+1.57$ (2) $+0.89$ (3) $-0.89$ (4) $-1.57$ 68. $How many grams of cobalt metal will be deposited when a solution ofcobalt (II) chloride is electrolyzed with a current of 10 amperes for 109 minutes (1 Faraday = 96, 500 C; Atomic mass of Co = 59 u)$ (1) $4.0$ (2) $20.0$ (3) $40.0$ (4) $0.66$ 69. $Which of the following electrolytic solutions has the least specific conductance?$ (1) $2 N$ (2) $0.002 N$ (3) $0.02 N$ (4) $0.2 N$ 70. $The molar conductivity of a 1.5 M solution of an electrolyte is found to be 138.9 S cm^{2} mol^{- 1} . The conductivity of this solution is$ (1) $1.325 S cm^{- 1}$ (2) $0.350 S cm^{- 1}$ (3) $0.208 S cm^{- 1}$ (4) $2.085 S cm^{- 1}$ 71. $The correct representation of Nernst equation for batscell reaction Cu_{(aq)}^{2 +} + e^{-} \to Cu_{(aq)}^{+} is$ (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) $none of the above$ 72. $Which one of the following graphs between molar conductivity (A_{m}) versus C is correct?$ (1) (2) (3) (4) 73. $O_{2} gas will be evolved as a product of electrolysis of: (A) an aqueous solution of AgNO3 using silver electrodes. (B) an aqueous solution of AgNO3 using platinum electrodes. (C) a dilute solution of H2SO4 using platinum electrodes. (D) a high concentration solution of H2SO4 using platinum electrodes. Choose the correct answer from the options given below:$ (1) $(A) and (C) only$ (2) $(B) and (C) only$ (3) $(A) and (D) only$ (4) $(B) and (D) only$ 74. $The standard emf of a galvanic cell involving 2 moles of electrons in its redox reaction is 0.59 V . The equilibrium constant for the redox reaction of the cell is$ (1) $10^{20}$ (2) $10^{5}$ (3) $10$ (4) $10^{10}$ 75. $For a Mg (Mg^{2 +} (aq)) (Ag^{+} (aq)) Ag the correct Nernst Equation is:$ (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) $E_{cell} = E_{cell}^{o} - \frac{RT}{2 F} ln \frac{( Mg ^{2 +} )}{( Ag ^{+} )}$ 76. $On passing a current of 1.2 A through a solution of salt of 40 min, 0.96 g of copper was deposited. The equivalent weight of copper in g is$ (1) $21.2$ (2) $31.75$ (3) $63.5$ (4) $15.9$ 77. $The equilibrium constant of the reaction: A_{(s)} + 2 B_{(aq)}^{+} ⇌ A_{(aq)}^{2 +} + 2 B_{(s)}; E_{cell}^{o} = 0.0295 V is (\frac{2.303 RT}{F} = 0.059)$ (1) $10$ (2) $2 \times 10^{2}$ (3) $3 \times 10^{2}$ (4) $2 \times 10^{5}$ 78. $A solution contains F e^{2 +}, F e^{3 +} and I^{-} ions. This solution was treated with iodine at 3 5^{o} C . E^{o} for F e^{3 +} / F e^{2 +} i s + 0.77 V and E^{o} for I_{2} /2 I^{-} = 0.536 V. The favourable redox reaction is$ (1) $I_{2} will be reduced to I^{-}$ (2) $there will be no redox reaction$ (3) $I^{-} will be oxidised to I_{2}$ (4) $F e^{2 +} will be oxidised to F e^{3 +}$ 79. $Match List-I with List-II. List-I (A) Cd(s)+2Ni (O H)_{3} (s) \to CdO(s)+2Ni (O H)_{2} (s)+ H_{2} O(l) (B) Zn(Hg)+HgO(s) \to ZnO(s)+Hg(l) (C) 2 P b S O_{4} (s)+ 2 H_{2} O(l) \to Pb(s)+ P b O_{2} (s)+ 2 H_{2} S O_{4} (aq) (D) 2 H_{2} (g)+ O_{2} (g) \to 2 H_{2} O(l) List-II (I) Primary battery (II) Discharging of secondary battery (III) Fuel cell (IV) Charging of secondary Choose the correct answer from the options given below:$ (1) $(A) - (I), (B) - (II), (C) - (III), (D) - (IV)$ (2) $(A) - (IV), (B) - (I), (C) - (II), (D) - (III)$ (3) $(A) - (II), (B) - (I), (C) - (IV), (D) - (III)$ (4) $(A) - (II), (B) - (I), (C) - (III), (D) - (IV)$ 80. $The number of Faradays ( F ) required to produce 20 g of calcium from molten CaCl_{2} (Atomic mass of Ca = 40 g mol^{- 1}) is$ (1) $2$ (2) $3$ (3) $4$ (4) $1$ 81. $9.65 C of electric current is passed through fused anhydrous magnesium chloride. The magnesium metal thus, obtained is completely converted into a Grignard reagent. The number of moles of the Grignard reagent obtained is$ (1) $5 \times 10^{- 4}$ (2) $1 \times 10^{- 4}$ (3) $5 \times 10^{- 5}$ (4) $1 \times 10^{- 5}$ 82. $The electrode potential of chlorine electrode is maximum, when the concentration of chloride ion in the solution (in molL L^{- 1}) is X . What is the value of X ?$ (1) $2.5 \times 10^{- 3}$ (2) $7.5 \times 10^{- 3}$ (3) $7.5 \times 10^{- 2}$ (4) $2.5 \times 10^{- 2}$ 83. $Λ_{m}^{\circ} for NaCl, HCl and NaA are 126.4, 425.9 and 100.5 S c m^{2} mo l^{- 1}, respectively. If the conductivity of 0.001 M HA is 5 \times 1 0^{- 5} S c m^{- 1}, degree of dissociation of HA is:$ (1) $0.50$ (2) $0.25$ (3) $0.125$ (4) $0.75$ 84. $Some statements about Lechlanche cell are (I) Anode is zinc metal (II) Cathode is graphite rod surrounded by powdered MnO_{2} and carbon (III)Electrolyte is a moist paste of ZnO and KOH (IV)Oxidation product is ZnO The correct statements are$ (1) $I & II only$ (2) $II & III only$ (3) $I & IV only$ (4) $I, II & III only$ 85. $In a typical fuel cell, the reactants (R) and product (P) are$ (1) $R = H_{2 (g)}, O_{2 (g)}; P = H_{2} O_{(l)}$ (2) $R = H_{2 (g)}, O_{2 (g)}, Cl_{2 (g)}; P = HClO_{4 (aq)}$ (3) $R = H_{2 (g)}, N_{2 (g)}; P = NH_{3 (qq)}$ (4) $R = H_{2 (g)}, O_{2 (g)}; P = H_{2} O_{2 (l)}$ 86. $The approximate time duration in hours to electroplate 30 g of calcium from molten calcium chloride using a current of 5 amp is [At. mass of Ca = 40]$ (1) $8$ (2) $80$ (3) $10$ (4) $16$ 87. $The resistance of 0.01 MKCl solution at 298 K is 1500Ω . If the conductivity of 0.01 M KCl solution at 298 K is 0.1466 \times 10^{- 3} S cm^{- 1} . The cell constant of the conductivity cell in (cm^{- 1}) is$ (1) $0.219$ (2) $0.291$ (3) $0.301$ (4) $0.194$ 88. $250 mL of a waste solution obtained from the workshop of goldsmith contains 0.1 M AgNO_{3} and 0.1 M AuCl. The solution was electrolyzed at 2V by passing a current of 1A for 15minutes. The metal/metals electrodeposited will be [E_{Ag^{+} \| Ag}^{0} = 0.80 V, E_{Au^{+} / Au}^{0} = 1.69 V]$ (1) $Silver and gold in equal mass proportion$ (2) $Silver and gold in proportion to their atomic weights$ (3) $Only gold$ (4) $Only silver$ 89. $Which of the following correctly represents Nernst equation? [P = products, R = reactants]$ (1) $Δ G = Δ G^{\circ} + 2.303 RT log \frac{[ P ]}{[ R ]}$ (2) $Δ G = Δ G^{\circ} - 2.303 RT log \frac{[ P ]}{[ R ]}$ (3) $Δ G^{\circ} = Δ G + 2.303 RT log \frac{[ R ]}{[ P ]}$ (4) $Δ G^{\circ} = Δ G - 2.303 RT log \frac{[ R ]}{[ P ]}$ 90. $During galvanization of iron, which metal is used ion coating iron surface?$ (1) $Copper$ (2) $Zinc$ (3) $Nickel$ (4) $Tin$