List of top Chemistry Questions on Electrochemistry asked in NEET (UG)

If the molar conductivity ($\Lambda_m$) of a 0.050 mol $L^{–1}$ solution of a monobasic weak acid is 90 S $cm^{2} mol^{–1}$, its extent (degree) of dissociation will be:
[Assume: $\Lambda^0$ = 349.6 S $cm^{2} mol^{–1}$ and $\Lambda^0_{\text{acid}}$ = 50.4 S$ cm^{2} mol^{–1}$]

The conductivity of centimolar solution of KCI at 25°C is 0.0210 ohm^-1cm^-1 and the resistance of the cell containing the solution at 25°C is 60 ohm. The value of the cell constant is :

Given below are two statements labeled Assertion A and the labeled as Reason R :
Assertion A: In the equation $\Delta_rG=-nFE_{cell}$ value of $\Delta_rG$ depends on n.
Reasons R: $E_{cell}$ is an intensive property and $\Delta_rG$ is an extensive property.
In the light of the above statements, choose the correct answer from the options below :

At 298 K, the standard electrode potentials of Cu²⁺/Cu, Zn²⁺/Zn, Fe²⁺/Fe and Ag⁺/Ag are 0.34 V, - 0.76 V, - 0.44 V and 0.80 V, respectively.
On the basis of standard electrode potential, predict which of the following reaction cannot occur?

Given below are half-cell reactions:
$MnO_4^- + 8H^+ + 5e^- → Mn^{2+} + 4H_2O$,
$E°_{(Mn^{+2}/MnO_4^-)} = –1.510 V$
$(\frac{1}{2})O_2 + 2H^+ + 2e^- → H_2O,$
$E°(O_2/H_2O) = +1.223 V$
Will the permanganate ion, $MnO_4^-$ liberate $O_2$ from water in the presence of an acid?

Find the emf of the cell

Ni(s) + 2 Ag⁺ (0.001 M) → Ni²⁺ (0.001 M) + 2Ag(s)

(Given that E°cell = 1.05 V, $\frac{2.303RT}{F} = 0.059$ at 298 K)

On electrolysis of dil.sulphuric acid using Platinum (Pt) electrode, the product obtained at anode will be:

In which case change in entropy is negative? (1)(2) (3 (4)

For a cell involving one electron $E^{\circ}_{cell}$ = 0.59 V at 298 K, the equilibrium constant for the cell reaction is : [ Given that $\frac{2.303\,RT}{F}$= 0.059 V at T=298 ]

Following limiting molar conductivities are given as $\lambda^{o}_{m}\left(H_{2}SO_{4}\right) \,= \,x S\, cm^{2} mol^{-1}$ $\lambda^{o}_{m}\left(K_{2}SO_{4}\right) = y S\,cm^{2} mol^{-1}$ $\lambda^{o}_{m}\left(CH_{3}COOK\right) =z S\, cm^{2} mol^{-1} $ $\lambda^{o}_{m}\left(in \,S \,cm^{2} mol^{-1}\right)$ for $CH_3COOH$ will be-

In the electrochemical cell :
$Zn|ZnSO_4(0.01M)||CuSO_4(1.0 M)|Cu,$
the emf of this Daniel cell is $E_1$. When the concentration of $ZnSO_4$ is changed to 1.0 M and that of $CuSO_4$ changed to 0.01 M, the emf changes to $E_2$. From the following, which one is the relationship between $E_1$ and $E_2$?
(Given, $\frac {RT}{F}= 0.059$)

Extraction of gold and silver involves leaching with CN^– ion. Silver is later recovered by

The e.m.f. of a Daniell cell at $298\, K$ is $E _{1}$. $Zn / SO _{4}(0.01 M ) \| CuSO _{4}(1.0 M ) / Cu$ When the concentration of $ZnSO _{4}$ is $1.0\, M$ and that of $CuSO _{4}$ is $0.01\, M$, the e.m.f. is changed to $E _{2}$. What is the relationship between $E _{1}$ and $E _{2}$ :

Zinc can be coated on iron to produce galvanized iron but the reverse is not possible. It is because

During the electrolysis of molten sodium chloride, the time required to produce $0.10$ mol of chlorine gas using a current of $3$ amperes is

A device that converts energy of combustion of fuels like hydrogen and methane, directly into electrical energy is known as

The weight of silver (at wt. = 108) displaced by a quantity of electricity which displaces 5600 mL of O₂ at STP will be:

When 0.1 mol MnO₄^2– is oxidised the quantity of electricity required to completely oxidise MnO4^2– to MnO₄^– is

At 25°C molar conductance of 0.1 molar aqueous solution of ammonium hydroxide is 9.54 ohm^-1 cm² mol^-1 and at infinite dilution its molar conductance is 238 ohm^-1 cm² mol^-1. The degree of ionisation of ammonium hydroxide at the same concentration and temperature is

A button cell used in watches functions as following
Zn(s) + Ag₂O(s) + H₂O(l) ⇌ 2Ag(s) + Zn²⁺ (aq) + 20H^- (aq)
If half cell potentials are
Zn²⁺(aq) + 2e^- → Zn(s); E° = -0.76 V
Ag₂O(s) + H₂O(l) + 2e^- → 2Ag(s) + 20H^-(aq),
E° = 0.34 V
The cell potential will be

Consider the half-cell reduction reaction :- $Mn^{2+}+2e^{-}\to Mn, E^{0}=-1.18 V$ $Mn^{2+}\to Mn^{3+}+e^{-}, E^{0}=-1.51 V$ The $E^\circ$ for the reaction $3 Mn^{2+}\to Mn^{0}+2Mn^{3+}$ and possibility of the forward reaction are respectively :

A button cell used in watches function as following Zn(s) + Ag₂O(s) + H₂O(l) $\rightleftharpoons$ 2Ag(s) + Zn²⁺(aq) + 2OH^-(aq). If half cell potentials are ${Zn^{2+}_{ (aq)} + 2e\to Zn(s); E^{\circ} = -0.76V}$ ${Ag2O_{(s)} + H2O_{(l)} + 2e\to 2Ag_{(s)} + 2OH^{-}_{(aq)};}$ $E^{\circ} = 0.34V$

How many grams of cobalt metal will be deposited when a solution of cobalt (II) chloride is electrolyzed with a current of 10 amperes for 109 minutes (1 Faraday = 96,500 C; Atomic mass of Co = 59 u) :

A hydrogen gas electrode is made by dipping platinum wire in a solution of HCl of pH = 10 and by passing hydrogen gas around the platinum wire at one atm pressure. The oxidation potential of electrode would be ?

Limiting molar conductivity of $NH_4OH $ $[i.e. \,\wedge^\circ {m (NH_4OH)}]$ is equal to