Electrochemistry PYQs Set 4 (PDF)

Set 4 of 13 · Questions 91-120 of 363

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Mere Teacher · Previous Year Questions JEE Main Chemistry · Electrochemistry · Set 4 (Q91-120)
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91. $Match List-I with List-II. List-I (A) Cd(s)+2Ni (O H)_{3} (s) \to CdO(s)+2Ni (O H)_{2} (s)+ H_{2} O(l) (B) Zn(Hg)+HgO(s) \to ZnO(s)+Hg(l) (C) 2 P b S O_{4} (s)+ 2 H_{2} O(l) \to Pb(s)+ P b O_{2} (s)+ 2 H_{2} S O_{4} (aq) (D) 2 H_{2} (g)+ O_{2} (g) \to 2 H_{2} O(l) List-II (I) Primary battery (II) Discharging of secondary battery (III) Fuel cell (IV) Charging of secondary Choose the correct answer from the options given below:$ (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) $(A) - (II), (B) - (I), (C) - (III), (D) - (IV)$ 92. $The number of Faradays ( F ) required to produce 20 g of calcium from molten CaCl_{2} (Atomic mass of Ca = 40 g mol^{- 1}) is$ (1) $2$ (2) $3$ (3) $4$ (4) $1$ 93. $9.65 C of electric current is passed through fused anhydrous magnesium chloride. The magnesium metal thus, obtained is completely converted into a Grignard reagent. The number of moles of the Grignard reagent obtained is$ (1) $5 \times 10^{- 4}$ (2) $1 \times 10^{- 4}$ (3) $5 \times 10^{- 5}$ (4) $1 \times 10^{- 5}$ 94. $The electrode potential of chlorine electrode is maximum, when the concentration of chloride ion in the solution (in molL L^{- 1}) is X . What is the value of X ?$ (1) $2.5 \times 10^{- 3}$ (2) $7.5 \times 10^{- 3}$ (3) $7.5 \times 10^{- 2}$ (4) $2.5 \times 10^{- 2}$ 95. $Λ_{m}^{\circ} for NaCl, HCl and NaA are 126.4, 425.9 and 100.5 S c m^{2} mo l^{- 1}, respectively. If the conductivity of 0.001 M HA is 5 \times 1 0^{- 5} S c m^{- 1}, degree of dissociation of HA is:$ (1) $0.50$ (2) $0.25$ (3) $0.125$ (4) $0.75$ 96. $Some statements about Lechlanche cell are (I) Anode is zinc metal (II) Cathode is graphite rod surrounded by powdered MnO_{2} and carbon (III)Electrolyte is a moist paste of ZnO and KOH (IV)Oxidation product is ZnO The correct statements are$ (1) $I & II only$ (2) $II & III only$ (3) $I & IV only$ (4) $I, II & III only$ 97. $In a typical fuel cell, the reactants (R) and product (P) are$ (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) $R = H_{2 (g)}, O_{2 (g)}; P = H_{2} O_{2 (l)}$ 98. $The approximate time duration in hours to electroplate 30 g of calcium from molten calcium chloride using a current of 5 amp is [At. mass of Ca = 40]$ (1) $8$ (2) $80$ (3) $10$ (4) $16$ 99. $The resistance of 0.01 MKCl solution at 298 K is 1500Ω . If the conductivity of 0.01 M KCl solution at 298 K is 0.1466 \times 10^{- 3} S cm^{- 1} . The cell constant of the conductivity cell in (cm^{- 1}) is$ (1) $0.219$ (2) $0.291$ (3) $0.301$ (4) $0.194$ 100. $250 mL of a waste solution obtained from the workshop of goldsmith contains 0.1 M AgNO_{3} and 0.1 M AuCl. The solution was electrolyzed at 2V by passing a current of 1A for 15minutes. The metal/metals electrodeposited will be [E_{Ag^{+} \| Ag}^{0} = 0.80 V, E_{Au^{+} / Au}^{0} = 1.69 V]$ (1) $Silver and gold in equal mass proportion$ (2) $Silver and gold in proportion to their atomic weights$ (3) $Only gold$ (4) $Only silver$ 101. $Which of the following correctly represents Nernst equation? [P = products, R = reactants]$ (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) $Δ G^{\circ} = Δ G - 2.303 RT log \frac{[ R ]}{[ P ]}$ 102. $During galvanization of iron, which metal is used ion coating iron surface?$ (1) $Copper$ (2) $Zinc$ (3) $Nickel$ (4) $Tin$ 103. $Given: Co^{3 +} + e^{-} \to Co^{2 +}; E^{0} = + 1.81 V Pb^{4 +} + 2 e^{-} \to Pb^{2 +}; E^{o} = + 1.67 V Ce^{4 +} + e^{-} \to Ce^{3 +}; E^{\circ} = + 1.61 V Bi^{3 +} + 3 e^{-} \to Bi; E^{\circ} = + 0.20 V oxidizing power of the species will increase in the order:$ (1) $Ce^{4 +} < Pb^{4 +} < Bi^{3 +} < Co^{3 +}$ (2) $Bi^{3 +} < Ce^{4 +} < Pb^{4 +} < Co^{3 +}$ (3) $Co^{3 +} < Ce^{4 +} < Bi^{3 +} < Pb^{4 +}$ (4) $Co^{3 +} < Pb^{4 +} < Ce^{4 +} < Bi^{3 +}$ 104. $The time required (in hours) to reduce 3 mol of Fe^{3 +} ions to Fe^{2 +} ions with 2.0 amperes of current is (1 F (= 96500 C mol^{- 1})$ (1) $30.2$ (2) $40.2$ (3) $10.2$ (4) $15.2$ 105. $The variation of λ_{m} of acetic acid with concentration is correctly represented as$ (1) (2) (3) (4) 106. $For the cell reaction 2 Fe^{3 +} (aq) + 2 I^{-} (aq) \to 2 Fe^{2 +} (aq) + I_{2} (aq) E_{cell}^{Θ} = 0.24 V at 298 K . The standard Gibbs energy (Δ_{r} G^{⊖}) of the cell reaction is [Given that Faraday constant F = 96500 C mol^{- 1}]$ (1) $-46.32 kJ mol^{- 1}$ (2) $-23.16 kJ mol^{- 1}$ (3) $46.32 kJ mol^{- 1}$ (4) $23.16 kJ mol^{- 1}$ 107. $Calculate current in ampere required to deposit 4.8 g Cu from its salt solution in 30 minutes. (Molar mass of Cu = 63.5 g mol^{- 1})$ (1) $8.1 ampere$ (2) $6.4 ampere$ (3) $10.5 ampere$ (4) $12.3 ampere$ 108. $The reduction potential of a half cell consisting of a Pt electrode immersed in 2.0 M Fe^{2 +} and 0.02 M Fe^{3 +} solution (in V) is Given (\frac{2.303 RT}{F} = 0.059, E_{Fe^{3 +} ∣ Fe^{2 +}}^{0} = 0.771 V)$ (1) $0.543$ (2) $0.653$ (3) $0.733$ (4) $0.822$ 109. $The reduction potential of hydrogen electrode at 25^{\circ} C in a neutral solution is (p_{H_{2}} = 1) bar)$ (1) $0.059 V$ (2) $- 0.059 V$ (3) $- 0.413 V$ (4) $0.0 V$ 110. $Find the observed EMF of the cell Cd ∣ Cd^{2 +} (0.01 M) ∥ Cu^{2 +} (0.01 M) ∣ Cu under conditions, internal resistance of 4Ω and producing a current of 0.15 A . (Given, E_{Cu^{2 +} / Cu}^{\circ} = 0.35 V and E^{\circ} Cd^{2 +} / Cd = - 0.4 V)$ (1) $0.75 V$ (2) $0.15 V$ (3) $0.6 V$ (4) $0.9 V$ 111. $For hydrogen - oxygen fuel cell at one atm and 298 K H_{2 (g)} + \frac{1}{2} O_{2 (g)} \to H_{2} O_{(l)}; Δ G^{\circ} = - 240 kJ E^{\circ} for the cell is approximately, (Given : F = 96, 500 C)$ (1) $2.48 V$ (2) $1.24 V$ (3) $2.5 V$ (4) $1.26 V$ 112. $Given E_{Fe^{+ 3} / Fe^{+ 2}}^{0} = + 0.76 V and E_{I_{2} / I^{-}}^{0} = + 0.55 V . The equilibrium constant for the reaction taking place in galvanic cell consisting of above two electrodes is (\frac{2.303 RT}{F} = 0.06)$ (1) $1 \times 10^{9}$ (2) $3 \times 10^{8}$ (3) $5 \times 10^{12}$ (4) $1 \times 10^{7}$ 113. $38.6 amperes of current is passed for 100 seconds through an aqueous CuSO_{4} solution using platinum electrodes. The mass of copper consumed from the solution and volume of gas liberated at STP are respectively (molar mass of (Cu = 63.54 g mol^{- 1}) .$ (1) $6.37 g, 0.448 L$ (2) $0.63 g, 0.224 L$ (3) $1.27 g, 0.224 L$ (4) $4 g, 0.448 L$ 114. $The product, which is not obtained during the electrolysis of brine solution is$ (1) $H_{2}$ (2) $HC1$ (3) $NaOH$ (4) $C 1_{2}$ 115. $What is the conductivity of 0.05 M BaCl_{2} solution if its molar conductivity is 220 Ω^{- 1} cm^{2} mol^{- 1} ?$ (1) $0.011 Ω^{- 1} cm^{- 1}$ (2) $0.033 Ω^{- 1} cm^{- 1}$ (3) $0.022 Ω^{- 1} cm^{- 1}$ (4) $0.044 Ω^{- 1} cm^{- 1}$ 116. $Calculate E_{cell}^{o} for Cd_{(s)} (Cd^{++} (1 M) ∥ Ag^{+} (1 M)) Ag_{(s)} (E_{Cd}^{o} = - 0.403 V; E_{Ag}^{o} = 0.799 V)$ (1) $1.202 V$ (2) $- 1.202 V$ (3) $0.396 V$ (4) $- 0.396 V$ 117. $The Gibbs energy change (in J) for the given reaction at (Cu^{2 +}) = (Sn^{2 +}) = 1 M and 298 K is: C u (s) + S n^{2 +} (aq) \to C u^{2 +} (aq) + Sn (s) (E_{S n^{2}}^{O} = - 0.16 V, E_{C u^{2 +} \| Cu}^{0} = 0.34 V; Take F = 96500 C mol^{- 1})$ 118. $Electrolysis of 600 mL aqueous solution of NaCl for 5 min changes the pH of the solution to 12. The current in Amperes used for the given electrolysis is . (Nearest integer).$ 119. $0.2 % (w / v) solution of NaOH is measured to have resistivity 870.0 mΩ m . The molar conductivity of the solution will be \times 10^{2} mSdm^{2} mol^{- 1} . (Nearest integer)$ 120. $Consider the following reaction Mn O_{4}^{-} + 8 H^{+} + 5 e^{-} \to M n^{+ 2} + 4 H_{2} O, E ° = 1.51 V The quantity of electricity required in Faraday to reduce five moles of Mn O_{4}^{-} is$