Electrochemistry PYQs Set 6 (PDF)

Set 6 of 13 · Questions 151-180 of 363

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Mere Teacher · Previous Year Questions JEE Main Chemistry · Electrochemistry · Set 6 (Q151-180)
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151. $For a strong electrolyte, a plot of molar conductivity against (concentration) 1/2 is a straight line, with a negative slope, the correct unit for the slope is$ (1) $Scm^{2} mol^{- 3/2} L^{- 1/2}$ (2) $Sc m^{2} mo l^{- 3/2} L^{1/2}$ (3) $Scm^{2} mol^{- 3/2} L$ (4) $Scm^{2} mol^{- 1} L^{1/2}$ 152. $Correct order of limiting molar conductivity for cations in water at 298 K is:$ (1) $H^{+} > Na^{+} > K^{+} > Ca^{2 +} > Mg^{2 +}$ (2) $H^{+} > Ca^{2 +} > Mg^{2 +} > K^{+} > Na^{+}$ (3) $Mg^{2 +} > H^{+} > Ca^{2 +} > K^{+} > Na^{+}$ (4) $H^{+} > Na^{+} > Ca^{2 +} > Mg^{2 +} > K^{+}$ 153. $Two Faraday of electricity is passed through a solution of C u S O_{4} . The mass of copper deposited at the cathode is : (at. mass of Cu = 63.5 amu)$ (1) $0 g$ (2) $63.5 g$ (3) $2 g$ (4) $127 g$ 154. $What is the molar conductivity of CH_{3} CO_{2} H at infinite dilution? Given that, \land_{m}^{\circ} (CH_{3} CO_{2})_{2} Ba = x_{1} S cm^{2} mol^{- 1} \land_{m}^{\circ} (BaCl_{2}) = x_{2} S cm^{2} mol^{- 1} \land_{m}^{o} (HCl) = x_{3} S cm^{2} mol^{- 1}$ (1) $\frac{x _{1} - x _{2}}{2} + x_{3}$ (2) $\frac{x _{1} - x _{3}}{2} + x_{2}$ (3) $\frac{x _{2} - x _{3}}{2} + x_{1}$ (4) $x_{1} + x_{3} - x_{2}$ 155. $The overall reaction taking place at anode during electrolysis of fused sodium chloride using suitable electrode is$ (1) $oxidation of chloride$ (2) $reduction of sodium ions$ (3) $reduction of chlorine$ (4) $oxidation of sodium atoms.$ 156. $The electrode potential for M^{2 +} (aq) + e^{-} ⟶ M^{+} (aq) M^{+} (aq) + e^{-} ⟶ M (s) are + 0.15 V and + 0.50 V respectively. The value of E^{\circ}_{M^{2 +} / M} will be$ (1) $0.150 V$ (2) $0.300 V$ (3) $0.325 V$ (4) $0.650 V$ 157. $The conductivity of centimolar solution of KCl at 25^{\circ} C is 0.0210 ohm^{- 1} cm^{- 1} and the. resistance of the cell containing the solution at 25^{\circ} C is 60 ohm . The value of cell constant is:$ (1) $3.34 cm^{- 1}$ (2) $3.28 cm^{- 1}$ (3) $1.34 cm^{- 1}$ (4) $1.26 cm^{- 1}$ 158. $Given below are two statements: Statement (I): Corrosion is an electrochemical phenomenon in which pure metal acts as an anode and impure metal as a cathode. Statement (II): The rate of corrosion is more in alkaline medium than in acidic medium. choose the correct answer from the options given below:$ (1) $Both Statement I and Statement II are true$ (2) $Statement I is false but Statement II is true$ (3) $Statement I is true but Statement II is false$ (4) $Both Statement I and Statement II are false$ 159. $Match List - I with List - II: List - I Applications (A) Transistors (B) Hearing aids (C) Invertors (D) Apollo space ship List - II Batteries/Cell (I) Anode - Zn / Hg; Cathode - HgO + C (II) Hydrogen fuel cell (III) Anode - Zn; Cathode - Carbon (IV) Anode -Pb; Cathode - Pb ∣ PbO_{2} Choose the correct answer from the options given below :$ (1) $(A)-(III), (B)-(II), (C)-(IV), (D)-(I)$ (2) $(A)-(II), (B)-(III), (C)-(IV), (D)-(I)$ (3) $(A)-(III), (B)-(I), (C)-(IV), (D)-(II)$ (4) $(A)-(IV), (B)-(III), (C)-(II), (D)-(I)$ 160. $When a current of 10 A is passes through molten AlCl_{3} for 1.608 minutes. The mass of Al deposited will be [Atomic mass of Al = 27 g]$ (1) $0.09 g$ (2) $0.81 g$ (3) $1.35 g$ (4) $0.27 g$ 161. $Consider the following electrodes: P = Zn^{2 +} (0.0001 M) / Zn; Q = Zn^{2 +} (0.1 M) / Zn; R = Zn^{2 +} (0.01 M) / Zn; S = Zn^{2 +} (0.001 M) / Zn E_{Zn / Zn^{2 +}}^{\circ} = - 0.76 V electrode potentials of the above electrode in volts are in the order$ (1) $P > S > R > Q$ (2) $Q > R > S > P$ (3) $S > R > Q > P$ (4) $P > Q > R > S$ 162. $Which from following expressions is used to find the cell potential of Cd_{(s)} (Cd_{(aq)}^{++}) / Cu_{(aq)}^{++} ∣ Cu_{(s)} cell at 25^{\circ} C ?$ (1) $E_{cell} = E_{cell}^{\circ} - 0.0296 log \frac{( Cd ^{++} )}{( Cu ^{++} )}$ (2) $E_{cell} = E_{cell}^{\circ} + 0.0296 log \frac{( Cd ^{++} )}{( Cu ^{++} )}$ (3) $E_{cell} = E_{cell}^{\circ} - 0.0592 log \frac{( Cu ^{++} )}{( Cd ^{++} )}$ (4) $E_{cell} = E_{cell}^{\circ} + 0.0592 log \frac{( Cu ^{++} )}{( Cd ^{++} )}$ 163. $Calculate Δ G^{\circ} for the cell Sn_{(s)} (Sn^{++} (1 M) ∥ Ag^{+} (1 M)) Ag_{(s)} at 25^{\circ} C (E_{cell}^{\circ} = 0.90 V) .$ (1) $- 173.7 kJ$ (2) $- 225.3 kJ$ (3) $- 100.2 kJ$ (4) $- 290.8 kJ$ 164. $One litre solution of MgCl_{2} is electrolyzed completely by passing a current of 1 A for 16 min 5 sec . The original concentration of MgCl_{2} solution was (Atomic mass of Mg = 24)$ (1) $5 \times 10^{- 3} M$ (2) $5 \times 10^{- 2} M$ (3) $0.5\times 1 0^{- 3} M$ (4) $1.0 \times 10^{- 2} M$ 165. $Resistance of a conductivity cell filled with 0.1 mol L^{- 1} NaCl is 100 ohm . If the resistance of the same cell when filled with 0.02 mol L^{- 1} NaCl solution is 258 ohm, the conductivity of 0.02 mol L^{- 1} NaCl solution is (Conductivity of 0.1 mol L^{- 1} NaCl is 1.29 S m^{- 1})$ (1) $1.0 S m^{- 1}$ (2) $0.2 S m^{- 1}$ (3) $2.0 S m^{- 1}$ (4) $0.5 S m^{- 1}$ 166. $Standard electrode potentials of three metals X, Y and Z are - 1.2 V, + 0.5 V and—3.0 V respectively. The reducing power of these metals will be$ (1) $Y > Z > X$ (2) $Y > X > Z$ (3) $Z > X > Y$ (4) $X > Y > Z$ 167. $In two separate experiments, the same quantity of electricity was passed through silver and gold solutions [Assume 't' constant] The amounts of Ag and Au deposited are 2.15 and 1.31 g, respectively. The valency of gold is [Atomic mass of Ag = 107.9; Au = 197]$ (1) $1$ (2) $2$ (3) $3$ (4) $4$ 168. $On electrolysis of dil sulphuric acid using Platinum (Pt) electrode, the product obtained at anode will be$ (1) $Oxygen gas$ (2) $H_{2} S gas$ (3) $SO_{2} gas$ (4) $Hydrogen gas$ 169. $Given: E_{C r^{3 +} / Cr}^{0} = - 0.72, E_{F e^{2 +} / Fe}^{0} = - 0.42 V The potential for the cell Cr \| Cr^{3 +} (0.1 M) \|\| Fe^{2 +} (0.01 M) \| Fe at 298 K is: (Take \frac{2.303 R ( 298 )}{F} = 0.06)$ (1) $0.339 V$ (2) $- 0.339 V$ (3) $- 0.26 V$ (4) $0.26 V$ 170. $The conductivity of a solution of concentration 0.1 mol L^{- 1} of a weak monobasic acid (HA) (in Scm^{- 1}) is (Given Λ_{HA}^{\circ} = 400 Scm^{2} mol^{- 1} and degree dissociation (α) of HA = 0.02)$ (1) $32 \times 10^{- 4}$ (2) $16 \times 10^{- 4}$ (3) $4 \times 10^{- 4}$ (4) $8 \times 10^{- 4}$ 171. $The conductivity of a solution containing 2.08 g of anhydrous barium chloride in 200 mL solution is 6 \times 10^{- 3} ohm^{- 1} cm^{- 1} . The molar conductivity of the solution (in ohm^{- 1} cm^{2} mol^{- 1}) is x \times 10^{2} . The value of x is (Atomic mass of Ba = 137, Cl = 35.5)$ (1) $1.2$ (2) $2.4$ (3) $3.6$ (4) $3.0$ 172. $The mass of carbon anode consumed (giving only carbon dioxide) in the production of 270 kg of aluminium metal from bauxite by the Hall process is$ (1) $270 kg$ (2) $540 kg$ (3) $90 kg$ (4) $180 kg (Atomic mass: Al = 27)$ 173. $The number of electrons delivered at the cathode during electrolysis by a current of 1 ampere in 60 seconds is (charge on electron = 1.60 \times 1 0^{- 19} C)$ (1) $6 \times 1 0^{23}$ (2) $6 \times 1 0^{20}$ (3) $3.75 \times 1 0^{20}$ (4) $7.48 \times 1 0^{23}$ 174. $Given below are two statementsAssertion (A): Conductivity of an electrolyte decreases on dilutionReason (R): On dilution number of ions per unit volume increasesThe correct answer is$ (1) $Both (A) and (R) are correct and (R) is the correct explanation of (A)$ (2) $Both (A) and (R) are correct and (R) is not the correct explanation of (A)$ (3) $(A) is correct but (R) is not correct$ (4) $(A) is not correct but (R) is correct$ 175. $The quantity of silver deposited when one coulomb charge is passed through AgNO_{3} solution :$ (1) $1 g of silver$ (2) $1 electrochemical equivalent of silver$ (3) $1 chemical equivalent of silver$ (4) $0.1 g atom of silver$ 176. $Consider the single electrode process 4 H^{+} + 4 e^{-} ⇌ 2 H_{2} catalysed the platinum black electrode in HCl electrolyte. The potential of the electrode is - 0.059 V . SHE. What is the concentration of the acid in the hydrogen half cell if the H_{2} pressure is 1 bar? 4 H^{+} + 4 e^{-} ⇌ 2 H_{2}$ (1) $1 M$ (2) $10 M$ (3) $0.1 M$ (4) $0.01 M$ 177. $The magnitude of the change in oxidising power of the MnO_{4}^{-} / Mn^{2 +} couple is x \times 10^{- 4} V, if the H^{+} concentration is decreased from 1M to 10^{- 4} at 25°C.(Assume concentration of and to besame on change in H^{+} concentration). The value of is ____ (Rounded off to the nearest integer) [Given: \frac{2303 RT}{F} = 0.059]$ 178. $A constant current was passed through a solution of AuCl_{4}^{-} ion between gold electrodes. After a period of 10.0 minutes, the increase in mass of cathode was 1.314 g . The total charge passed through the solution is________\times 10^{- 2} F . (Given atomic mass of Au = 197)$ 179. $The resistance of conductivity cell containing 0.01 M KC1 solution at 298 K is 1750 Ω . If the conductively of 0.01 M KC1 solution at 298 K is 0.152 x 1 0^{- 3} S c m^{- 1}, then the cell constant of the conductivity cell is_______x 1 0^{- 3} c m^{- 1} .$ 180. $For an electrochemical cell Sn (s) (S n^{2 +} (aq, 1 M)) (P b^{2} + (aq, 1 M)) Pb (s) the ratio \frac{( S n ^{2 +} )}{( P b ^{2 +} )} when this cell attains equilibrium is\dots\dots. (E °_{S n^{2 +} / Sn} = - 0.14 V, E °_{p b^{2} / pb} = - 0.13 V, \frac{2.303 RT}{F} = 0.06) Multiply your answer with 100 .$