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MCQ (Single Correct Answer)

1

Match List - I with List - II :

List - I (Applications) List - II (Batteries/Cell)
(A) Transistors (I) Anode - Zn/Hg; Cathode - HgO + C
(B) Hearing aids (II) Hydrogen fuel cell
(C) Inverters (III) Anode - Zn; Cathode - Carbon
(D) Apollo space ship (IV) Anode - Pb; Cathode - Pb | PbO2

Choose the correct answer from the options given below :

JEE Main 2025 (Online) 29th January Evening Shift
2

$\mathrm{O}_2$ gas will be evolved as a product of electrolysis of :

(A) an aqueous solution of $\mathrm{AgNO}_3$ using silver electrodes.

(B) an aqueous solution of $\mathrm{AgNO}_3$ using platinum electrodes.

(C) a dilute solution of $\mathrm{H}_2 \mathrm{SO}_4$ using platinum electrodes.

(D) a high concentration solution of $\mathrm{H}_2 \mathrm{SO}_4$ using platinum electrodes.

Choose the correct answer from the options given below :

JEE Main 2025 (Online) 29th January Evening Shift
3

For a Mg | Mg2+ (aq) || Ag+ (aq) | Ag the correct Nernst Equation is :

JEE Main 2025 (Online) 29th January Morning Shift
4

The molar conductivity of a weak electrolyte when plotted against the square root of its concentration, which of the following is expected to be observed?

JEE Main 2025 (Online) 29th January Morning Shift
5

The standard reduction potential values of some of the p-block ions are given below. Predict the one with the strongest oxidising capacity.

JEE Main 2025 (Online) 29th January Morning Shift
6

Based on the data given below :

$$\begin{array}{ll} \mathrm{E}_{\mathrm{Cr}_2 \mathrm{O}_7^{2-} / \mathrm{Cr}^{3+}}^{\circ}=1.33 \mathrm{~V} & \mathrm{E}_{\mathrm{Cl}_2 / \mathrm{Cl}^{(-)}}^{\circ}=1.36 \mathrm{~V} \\ \mathrm{E}_{\mathrm{MnO}_4^{-} / \mathrm{Mn}^{2+}}^0=1.51 \mathrm{~V} & \mathrm{E}_{\mathrm{Cr}^{3+} / \mathrm{Cr}}^{\circ}=-0.74 \mathrm{~V} \end{array}$$

the strongest reducing agent is :

JEE Main 2025 (Online) 24th January Evening Shift
7

For the given cell

$$\mathrm{Fe}^{2+}(\mathrm{aq})+\mathrm{Ag}_{(\mathrm{aq})}^{+} \rightarrow \mathrm{Fe}^{3+}(\mathrm{aq})+\mathrm{Ag}_{(\mathrm{s})}$$

The standard cell potential of the above reaction is Given:

$$\begin{array}{lr} \mathrm{Ag}^{+}+\mathrm{e}^{-} \rightarrow \mathrm{Ag} & \mathrm{E}^\theta=\mathrm{xV} \\ \mathrm{Fe}^{2+}+2 \mathrm{e}^{-} \rightarrow \mathrm{Fe} & \mathrm{E}^\theta=\mathrm{yV} \\ \mathrm{Fe}^{3+}+3 \mathrm{e}^{-} \rightarrow \mathrm{Fe} & \mathrm{E}^\theta=\mathrm{zV} \end{array}$$

JEE Main 2025 (Online) 24th January Morning Shift
8

Standard electrode potentials for a few half cells are mentioned below :

$$\begin{aligned} & \mathrm{E}_{\mathrm{Cu}^{2+} / \mathrm{Cu}}^{\circ}=0.34 \mathrm{~V}, \mathrm{E}_{\mathrm{Zn}^{2+} / \mathrm{Zn}}^{\circ}=-0.76 \mathrm{~V} \\ & \mathrm{E}_{\mathrm{Ag}^{+} / \mathrm{Ag}}^{\circ}=0.80 \mathrm{~V}, \mathrm{E}_{\mathrm{Mg}^{2+} / \mathrm{Mg}}^{\circ}=-2.37 \mathrm{~V} \end{aligned}$$

Which one of the following cells gives the most negative value of $\Delta \mathrm{G}^{\circ}$ ?

JEE Main 2025 (Online) 23rd January Evening Shift
9

$$ \mathrm{FeO}_4^{2-} \xrightarrow{+2.0 \mathrm{~V}} \mathrm{Fe}^{3+} \xrightarrow{0.8 \mathrm{~V}} \mathrm{Fe}^{2+} \xrightarrow{-0.5 \mathrm{~V}} \mathrm{Fe}^0 $$

In the above diagram, the standard electrode potentials are given in volts (over the arrow).

The value of $\mathrm{E}_{\mathrm{FeO}_4^{2-} / \mathrm{Fe}^{2+}}$ is :

JEE Main 2025 (Online) 23rd January Morning Shift
10

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.

In the light of the above statements, choose the correct answer from the options given below :

JEE Main 2025 (Online) 22nd January Evening Shift
11

Which of the following electrolyte can be used to obtain $\mathrm{H}_2 \mathrm{~S}_2 \mathrm{O}_8$ by the process of electrolysis ?

JEE Main 2025 (Online) 22nd January Morning Shift
12

A solution of aluminium chloride is electrolysed for 30 minutes using a current of 2 A . The amount of the aluminium deposited at the cathode is __________ .

[Given : molar mass of aluminium and chlorine are $27 \mathrm{~g} \mathrm{~mol}^{-1}$ and $35.5 \mathrm{~g} \mathrm{~mol}^{-1}$ respectively. Faraday constant $\left.=96500 \mathrm{C} \mathrm{~mol}^{-1}\right]$

JEE Main 2025 (Online) 22nd January Morning Shift
13

Match List I with List II

LIST I
(Cell)
LIST II
(Use/Property/Reaction)
A. Leclanche cell I. Converts energy of combustion into electrical energy
B. Ni - Cd cell II. Does not involve any ion in solution and is used in hearing aids
C. Fuel cell III. Rechargeable
D. Mercury cell IV. Reaction at anode $$\mathrm{Zn} \rightarrow \mathrm{Zn}^{2+}+2 \mathrm{e}^{-}$$

Choose the correct answer from the options given below :

JEE Main 2024 (Online) 9th April Evening Shift
14

Which out of the following is a correct equation to show change in molar conductivity with respect to concentration for a weak electrolyte, if the symbols carry their usual meaning :

JEE Main 2024 (Online) 9th April Evening Shift
15

The molar conductivity for electrolytes $$A$$ and $$B$$ are plotted against $$C^{3 / 2}$$ as shown below. Electrolytes $$A$$ and $$B$$ respectively are:

JEE Main 2024 (Online) 9th April Morning Shift Chemistry - Electrochemistry Question 28 English

JEE Main 2024 (Online) 9th April Morning Shift
16

The emf of cell $$\mathrm{Tl}\left|\underset{(0.001 \mathrm{M})}{\mathrm{Tl}^{+}}\right| \underset{(0.01 \mathrm{M})}{\mathrm{Cu}^{2+}} \mid \mathrm{Cu}$$ is $$0.83 \mathrm{~V}$$ at $$298 \mathrm{~K}$$. It could be increased by :

JEE Main 2024 (Online) 8th April Evening Shift
17

The reaction;

$$\frac{1}{2} \mathrm{H}_{2(\mathrm{~g})}+\mathrm{AgCl}_{(\mathrm{s})} \rightarrow \mathrm{H}_{(\mathrm{aq})}^{+}+\mathrm{Cl}_{(\mathrm{aq})}^{-}+\mathrm{Ag}_{(\mathrm{s})}$$

occurs in which of the following galvanic cell :

JEE Main 2024 (Online) 8th April Evening Shift
18

Given below are two statements :

Statement (I) : Fusion of $$\mathrm{MnO}_2$$ with $$\mathrm{KOH}$$ and an oxidising agent gives dark green $$\mathrm{K}_2 \mathrm{MnO}_4$$.

Statement (II) : Manganate ion on electrolytic oxidation in alkaline medium gives permanganate ion.

In the light of the above statements, choose the correct answer from the options given below :

JEE Main 2024 (Online) 8th April Evening Shift
19

How can an electrochemical cell be converted into an electrolytic cell ?

JEE Main 2024 (Online) 6th April Evening Shift
20

A conductivity cell with two electrodes (dark side) are half filled with infinitely dilute aqueous solution of a weak electrolyte. If volume is doubled by adding more water at constant temperature, the molar conductivity of the cell will -

JEE Main 2024 (Online) 6th April Morning Shift Chemistry - Electrochemistry Question 15 English

JEE Main 2024 (Online) 6th April Morning Shift
21

The quantity of silver deposited when one coulomb charge is passed through $$\mathrm{AgNO}_3$$ solution :

JEE Main 2024 (Online) 5th April Evening Shift
22

For the electro chemical cell

$$\mathrm{M}\left|\mathrm{M}^{2+}\right||\mathrm{X}| \mathrm{X}^{2-}$$

If $$\mathrm{E}_{\left(\mathrm{M}^{2+} / \mathrm{M}\right)}^0=0.46 \mathrm{~V}$$ and $$\mathrm{E}_{\left(\mathrm{x} / \mathrm{x}^{2-}\right)}^0=0.34 \mathrm{~V}$$.

Which of the following is correct?

JEE Main 2024 (Online) 5th April Evening Shift
23

Molar ionic conductivities of divalent cation and anion are $$57 \mathrm{~S~cm}^2 \mathrm{~mol}^{-1}$$ and $$73 \mathrm{~S~cm}^2 \mathrm{~mol}^{-1}$$ respectively. The molar conductivity of solution of an electrolyte with the above cation and anion will be:

JEE Main 2024 (Online) 5th April Morning Shift
24

The reaction at cathode in the cells commonly used in clocks involves.

JEE Main 2024 (Online) 5th April Morning Shift
25

Fuel cell, using hydrogen and oxygen as fuels,

A. has been used in spaceship

B. has as efficiency of $$40 \%$$ to produce electricity

C. uses aluminum as catalysts

D. is eco-friendly

E. is actually a type of Galvanic cell only

Choose the correct answer from the options given below:

JEE Main 2024 (Online) 4th April Evening Shift
26

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

JEE Main 2024 (Online) 4th April Evening Shift
27

One of the commonly used electrode is calomel electrode. Under which of the following categories, calomel electrode comes?

JEE Main 2024 (Online) 4th April Morning Shift
28

What pressure (bar) of $$\mathrm{H}_2$$ would be required to make emf of hydrogen electrode zero in pure water at $$25^{\circ} \mathrm{C}$$ ?

JEE Main 2024 (Online) 4th April Morning Shift
29

Identify the factor from the following that does not affect electrolytic conductance of a solution.

JEE Main 2024 (Online) 31st January Morning Shift
30

Alkaline oxidative fusion of $$\mathrm{MnO}_2$$ gives "A" which on electrolytic oxidation in alkaline solution produces B. A and B respectively are

JEE Main 2024 (Online) 30th January Evening Shift
31

Reduction potential of ions are given below:

$$\begin{array}{ccc} \mathrm{ClO}_4^{-} & \mathrm{IO}_4^{-} & \mathrm{BrO}_4^{-} \\ \mathrm{E}^{\circ}=1.19 \mathrm{~V} & \mathrm{E}^{\circ}=1.65 \mathrm{~V} & \mathrm{E}^{\circ}=1.74 \mathrm{~V} \end{array}$$

The correct order of their oxidising power is :

JEE Main 2024 (Online) 30th January Evening Shift
32

Which of the following statements is not correct about rusting of iron?

JEE Main 2024 (Online) 27th January Evening Shift
33

For lead storage battery pick the correct statements

A. During charging of battery, $$\mathrm{PbSO}_{4}$$ on anode is converted into $$\mathrm{PbO}_{2}$$

B. During charging of battery, $$\mathrm{PbSO}_{4}$$ on cathode is converted into $$\mathrm{PbO}_{2}$$

C. Lead storage battery consists of grid of lead packed with $$\mathrm{PbO}_{2}$$ as anode

D. Lead storage battery has $$\sim 38 \%$$ solution of sulphuric acid as an electrolyte

Choose the correct answer from the options given below:

JEE Main 2023 (Online) 12th April Morning Shift
34

The reaction

$$\frac{1}{2} \mathrm{H}_{2}(\mathrm{~g})+\mathrm{AgCl}(\mathrm{s}) \rightleftharpoons \mathrm{H}^{+}(\mathrm{aq})+\mathrm{Cl}^{-}(\mathrm{aq})+\mathrm{Ag}(\mathrm{s})$$

occurs in which of the given galvanic cell.

JEE Main 2023 (Online) 8th April Morning Shift
35

The standard electrode potential of $$\mathrm{M}^{+} / \mathrm{M}$$ in aqueous solution does not depend on

JEE Main 2023 (Online) 6th April Morning Shift
36

Given below are two statements : one is labelled as Assertion (A) and the other is labelled as Reason (R)

Assertion (A) : An aqueous solution of $$\mathrm{KOH}$$ when used for volumetric analysis, its concentration should be checked before the use.

Reason (R) : On aging, $$\mathrm{KOH}$$ solution absorbs atmospheric $$\mathrm{CO}_{2}$$.

In the light of the above statements, choose the correct answer from the options given below :

JEE Main 2023 (Online) 1st February Evening Shift
37

Which one of the following statements is correct for electrolysis of brine solution?

JEE Main 2023 (Online) 31st January Morning Shift
38

The standard electrode potential $$\mathrm{(M^{3+}/M^{2+})}$$ 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 $$\mathrm{H_2}$$ from a dilute acid are :

JEE Main 2023 (Online) 29th January Morning Shift
39

Choose the correct representation of conductometric titration of benzoic acid vs sodium hydroxide.

JEE Main 2023 (Online) 24th January Evening Shift
40

Match List - I with List - II.

List - I List - II
(A) $$Cd(s) + 2Ni{(OH)_3}(s) \to CdO(s) + 2Ni{(OH)_2}(s) + {H_2}O(l)$$ (I) Primary battery
(B) $$Zn(Hg) + HgO(s) \to ZnO(s) + Hg(l)$$ (II) Discharging of secondary battery
(C) $$2PbS{O_4}(s) + 2{H_2}O(l) \to Pb(s) + Pb{O_2}(s) + 2{H_2}S{O_4}(aq)$$ (III) Fuel cell
(D) $$2{H_2}(g) + {O_2}(g) \to 2{H_2}O(l)$$ (IV) Charging of secondary battery

Choose the correct answer from the options given below:

JEE Main 2022 (Online) 28th July Morning Shift
41

Given below are two statements :

Statement I : For KI, molar conductivity increases steeply with dilution

Statement II : For carbonic acid, molar conductivity increases slowly with dilution

In the light of the above statements, choose the correct answer from the options given below :

JEE Main 2022 (Online) 27th July Evening Shift
42

The molar conductivity of a conductivity cell filled with 10 moles of 20 mL NaCl solution is $${\Lambda _{m1}}$$ and that of 20 moles another identical cell heaving 80 mL NaCl solution is $${\Lambda _{m2}}$$. The conductivities exhibited by these two cells are same. The relationship between $${\Lambda _{m2}}$$ and $${\Lambda _{m1}}$$ is

JEE Main 2022 (Online) 25th July Evening Shift
43

In which of the following half cells, electrochemical reaction is pH dependent?

JEE Main 2022 (Online) 30th June Morning Shift
44

In 3d series, the metal having the highest M2+/M standard electrode potential is :

JEE Main 2022 (Online) 27th June Evening Shift
45

The $${\left( {{{\partial E} \over {\partial T}}} \right)_P}$$ of different types of half cells are as follows:

A B C D
$$1 \times {10^{ - 4}}$$ $$2 \times {10^{ - 4}}$$ $$0.1 \times {10^{ - 4}}$$ $$0.2 \times {10^{ - 4}}$$

(Where E is the electromotive force)

Which of the above half cells would be preferred to be used as reference electrode?

JEE Main 2022 (Online) 26th June Morning Shift
46

The correct order of reduction potentials of the following pairs is

A. Cl2/Cl$$-$$

B. I2/I$$-$$

C. Ag+/Ag

D. Na+/Na

E. Li+/Li

Choose the correct answer from the options given below.

JEE Main 2022 (Online) 25th June Evening Shift
47
Match List - I with List - II

List - I
(Parmeter)
List - II
(Unit)
(a) Cell constant (i) $$S\,c{m^2}mo{l^{ - 1}}$$
(b) Molar conductivity (ii) Dimensionless
(c) Conductivity (iii) $${m^{ - 1}}$$
(d) Degree of dissociation of electrolyte (iv) $${\Omega ^{ - 1}}{m^{ - 1}}$$


Choose the most appropriate answer from the options given below :
JEE Main 2021 (Online) 31st August Evening Shift
48
Given below are two statements :

Statement I : The limiting molar conductivity of KCl (strong electrolyte) is higher compared to that of CH3COOH (weak electrolyte).

Statement II : Molar conductivity decreases with decrease in concentration of electrolyte.

In the light of the above statements, choose the most appropriate answer from the options given below :
JEE Main 2021 (Online) 26th August Morning Shift
49
Compound A used as a strong oxidizing agent is amphoteric in nature. It is the part of lead storage batteries. Compound A is :
JEE Main 2021 (Online) 26th February Morning Shift
50
The electrode potential of M2+/M of 3d-series elements shows positive value for :
JEE Main 2021 (Online) 24th February Morning Shift
51
For the given cell :

Cu(s) | Cu2+(C1M) || Cu2+(C2M) | Cu(s)

change in Gibbs energy ($$\Delta $$G) is negative, if :
JEE Main 2020 (Online) 6th September Evening Slot
52
The variation of molar conductivity with concentration of an electrolyte (X) in aqueous solution is shown in the given figure. JEE Main 2020 (Online) 5th September Evening Slot Chemistry - Electrochemistry Question 121 English
The electrolyte X is :
JEE Main 2020 (Online) 5th September Evening Slot
53
250 mL of a waste solution obtained from the workshop of a goldsmith contains 0.1 M AgNO3 and 0.1 M AuCl. The solution was electrolyzed at 2V by passing a current of 1A for 15 minutes. The metal/metals electrodeposited will be

[ $$E_{A{g^ + }/Ag}^0$$ = 0.80 V, $$E_{A{u^ + }/Au}^0$$ = 1.69 V ]
JEE Main 2020 (Online) 4th September Evening Slot
54
JEE Main 2020 (Online) 4th September Morning Slot Chemistry - Electrochemistry Question 124 English
$$E_{C{u^{2 + }}|Cu}^0$$ = +0.34 V

$$E_{Z{n^{2 + }}|Zn}^0$$ = -0.76 V

Identify the incorrect statement from the option below for the above cell :
JEE Main 2020 (Online) 4th September Morning Slot
55
Let CNaCl and CBaSO4 be the conductances (in S) measured for saturated aqueous solutions of NaCl and BaSO4, respectively, at a temperature T. Which of the following is false?
JEE Main 2020 (Online) 3rd September Morning Slot
56
The equation that is incorrect is :
JEE Main 2020 (Online) 7th January Evening Slot
57
Given that the standard potentials (Eo) of Cu2+/Cu and Cu+/Cu are 0.34 V and 0.522 V respectively, the Eo of Cu2+/Cu+ :
JEE Main 2020 (Online) 7th January Morning Slot
58
Given

CO3+ + e $$ \to $$ CO2+ ; Eo = + 1.81 V

Pb4+ + 2e $$ \to $$ Pb2+ ; Eo = + 1.67 V

Ce4+ + e $$ \to $$ Ce3+ ; Eo = + 1.61 V

Bi3+ + 3e $$ \to $$ Bi ; Eo = + 0.20 V

Oxidizing power of the species will increase in the order :
JEE Main 2019 (Online) 12th April Morning Slot
59
Which one of the following graphs between molar conductivity ($${\Lambda _m}$$) versus $$\sqrt C $$ is correct ?
JEE Main 2019 (Online) 10th April Evening Slot
60
Consider the statements S1 and S2

S1 : Conductivity always increases with decrease in the concentration of electrolyte.

S2 : Molar conductivity always increases with decrease in the concentration of electrolyte.

The correct option among the following is :
JEE Main 2019 (Online) 10th April Morning Slot
61
A solution of Ni(NO3)2 is electrolysed between platinum electrodes using 0.1 Faraday electricity. How many mole of Ni will be deposited at the cathode?
JEE Main 2019 (Online) 9th April Evening Slot
62
The standard Gibbs energy for the given cell reaction in kJ mol–1 at 298 K is :

Zn(s) + Cu2+ (aq) $$ \to $$ Zn2+ (aq) + Cu (s),

E° = 2 V at 298 K

(Faraday's constant, F = 96000 C mol–1)
JEE Main 2019 (Online) 9th April Morning Slot
63
Calculate the standard cell potential in (V) of the cell in which following reaction takes place :

Fe2+(aq) + Ag+(aq) $$ \to $$ Fe3+(aq) + Ag (s)

Given that

$$E_{A{g^ + }/Ag}^o = xV$$

$$E_{Fe^{2+ }/Fe}^o = yV$$

$$E_{Fe^{3+ }/Fe}^o = zV$$
JEE Main 2019 (Online) 8th April Evening Slot
64
Given that $${E^\Theta }_{{O_2}/{H_2}O} = 1.23\,V$$ ;

$${E^\Theta }_{{S_2}O_8^{2 - }/SO_4^{2 - }} = 2.05\,V$$

$${E^\Theta }_{B{r_2}/B{r^ - }} = 1.09\,V$$

$${E^\Theta }_{A{u^{3 + }}/Au} = 1.4\,V$$

The strongest oxidizing agent is :
JEE Main 2019 (Online) 8th April Morning Slot
65
$$ \wedge _m^ \circ $$ for NaCl, HCl and NaA are 126.4, 425.9 and 100.5 S cm2 mol–1, respectively. If the conductivity of 0.001 M HA is-

5 $$ \times $$ 10–5 S cm–1, degree of dissociation of HA is -
JEE Main 2019 (Online) 12th January Evening Slot
66
The standard electrode potential $${E^o }$$ and its temperature coefficient $$\left( {{{d{E^o }} \over {dT}}} \right)$$ for a cell are 2V and $$-$$ 5 $$ \times $$ 10$$-$$4 VK$$-$$1 at 300 K respectively.
The cell reaction is
Zn(s) + Cu2+ (aq) $$\buildrel \, \over \longrightarrow $$ Zn2+ (aq) + Cu(s)

The standard reaction enthalpy ($$\Delta $$rH$${^o }$$) at 300 K in kJ mol–1 is, [Use R = 8 JK–1 mol–1 and F = 96,000C mol–1]
JEE Main 2019 (Online) 12th January Morning Slot
67
Given the equilibrium constant:

KC of the reaction :

Cu(s) + 2Ag+ (aq) $$ \to $$ Cu2+ (aq) + 2Ag(s) is

10 $$ \times $$ 1015, calculate the E$$_{cell}^0$$ of this reaciton at 298 K

[2.303 $${{RT} \over F}$$ at 298 K = 0.059V]
JEE Main 2019 (Online) 11th January Evening Slot
68
For the cell Zn(s) |Zn2+ (aq)| |Mx+ (aq)| M(s), different half cells and their standard electrode potentials are given below :

Mx+ (aq)/M(s) Au3+(aq)/Au(s) Ag+(aq)/Ag(s) Fe3+(aq)/Fe2+ (aq) Fe2+(aq)/Fe(s)
E0Mx+/M/(V) 1.40 0.80 0.77 $$-$$0.44


If $$E_{z{n^{2 + }}/zn}^0$$ = $$-$$ 0.76 V, which cathode will give maximum value of Eocell per electron transferred?
JEE Main 2019 (Online) 11th January Morning Slot
69
In the cell

Pt$$\left| {\left( s \right)} \right|$$H2(g, 1 bar)$$\left| {HCl\left( {aq} \right)} \right|$$AgCl$$\left| {\left( s \right)} \right|$$Ag(s)|Pt(s)

the cell potential is 0.92 V when a 10–6 molal HCl solution is used. The standard electrode potential of (AgCl/ AgCl ) electrode is :
$$\left\{ {} \right.$$Given,  $${{2.303RT} \over F} = 0.06V$$  at  $$\left. {298} \right\}$$
JEE Main 2019 (Online) 10th January Evening Slot
70
Consider the following reduction processes :
Zn2+ + 2e $$ \to $$ Zn(s) ; Eo = – 0.76 V
Ca2+ + 2e $$ \to $$ Ca(s); Eo = –2.87 V
Mg2+ + 2e $$ \to $$ Mg(s) ; Eo = – 2.36 V
Ni2 + 2e $$ \to $$ Ni(s) ; Eo = – 0.25
The reducing power of the metals increases in the order :
JEE Main 2019 (Online) 10th January Morning Slot
71
If the standard electrode potential for a cell is 2 V at 300 K, the equilibrium constant (K) for the reaction

Zn(s) + Cu2+ (aq) $$\rightleftharpoons$$ Zn2+(aq) + Cu(s)

at 300 K is approximately,

(R = 8 JK$$-$$1mol$$-$$1, F = 96000 C mol$$-$$1)
JEE Main 2019 (Online) 9th January Evening Slot
72
The anodic half-cell of lead-acid battery is recharged using electricity of 0.05 Faraday. The amount of PbSO4 electrolyzed in g during the process is : (Molar mass of PbSO4 = 303 g mol$$-$$1)
JEE Main 2019 (Online) 9th January Morning Slot
73
When 9.65 ampere current was passed for 1.0 hour into nitrobenzene in acidic medium, the amount of p-aminophenol produced is :
JEE Main 2018 (Online) 16th April Morning Slot
74
How long (approximate) should water be electrolysed by passing through 100 amperes current so that the oxygen released can completely burn 27.66 g of diborane?
(Atomic weight of B = 10.8 u)
JEE Main 2018 (Offline)
75
When an electric currents passed through acidified water, 112 mL of hydrogen gas at N.T.P. was collected at the cathode in 965 seconds. The current passed, in ampere, is :
JEE Main 2018 (Online) 15th April Morning Slot
76
To find the standard potential of M3+/M electrode,the following cell is constituted : Pt/M/M3+(0.001 mol L−1 )/Ag+(0.01 mol L−1 )/Ag

The emf of the cell is found to be 0.421 volt at 298 K. The standard potential of half reaction M3+ + 3e$$ \to $$ M at 298 K will be :

(Given $$E_{A{g^ + }\,/\,Ag}^ - $$ at 298 K = 0.80 Volt)
JEE Main 2017 (Online) 9th April Morning Slot
77
Consider the following standard electrode potentials (Eo in volts) in aqueous solution :

Element M3+ /M M+ /M
A1 -1.66 + 0.55
T1 +1.26 - 0.34


Based on these data, which of the following statements is correct ?
JEE Main 2017 (Online) 8th April Morning Slot
78
What is the standard reduction potential (Eo) for Fe3+ $$ \to $$ Fe ?
Given that :
Fe2+ + 2e$$-$$ $$ \to $$ Fe; $$E_{F{e^{2 + }}/Fe}^o$$ = $$-$$0.47 V
Fe3+ + e$$-$$ $$ \to $$ Fe2+; $$E_{F{e^{3 + }}/F{e^{2 + }}}^o$$ = +0.77 V
JEE Main 2017 (Online) 8th April Morning Slot
79
Given
$$E_{C{l_2}/C{l^ - }}^o$$ = 1.36 V, $$E_{C{r^{3 + }}/Cr}^o$$ = - 0.74 V
$$E_{C{r_2}{O_7}^{2 - }/C{r^{3 + }}}^o$$ = 1.33 V, $$E_{Mn{O_4}^ - /Mn ^{2+}}^o$$ = 1.51 V
Among the following, the strongest reducing agent is :
JEE Main 2017 (Offline)
80
Identify the correct statement :
JEE Main 2016 (Online) 10th April Morning Slot
81
Oxidation of succinate ion produces ethylene and carbon dioxide gases. On passing 0.2 Faraday electricity through an aqueous solution of potassium succinate, the total volume of gases (at both cathode and anode) at STP (1 atm and 273 K) is :
JEE Main 2016 (Online) 10th April Morning Slot
82
What will occur if a block of copper metal is dropped into a beaker containing a solution of 1M ZnSO4?
JEE Main 2016 (Online) 9th April Morning Slot
83
Galvanization is applying a coating of :
JEE Main 2016 (Offline)
84
Two Faraday of electricity is passed through a solution of CuSO4. The mass of copper deposited at the cathode is: (at. mass of Cu = 63.5 amu)
JEE Main 2015 (Offline)
85
Given below are the half-cell reactions:

Mn2+ + 2e- $$\to$$ Mn; Eo = -1.18 V

2(Mn3+ + e- $$\to$$ Mn2+); Eo = +1.51 V

The Eo for 3Mn2+ $$\to$$ Mn + 2Mn3+ will be :
JEE Main 2014 (Offline)
86
The equivalent conductance of NaCl at concentration C and at infinite dilution are $${\lambda _C}$$ and $${\lambda _\infty }$$, respectively. The correct relationship between $${\lambda _C}$$ and $${\lambda _\infty }$$ is given as: (where the constant B is positive)
JEE Main 2014 (Offline)
87
Resistance of 0.2 M solution of an electrolyte is 50 $$\Omega$$. The specific conductance of the solution is 1.4 S m-1. The resistance of 0.5 M solution of the same electrolyte is 280 $$\Omega$$. The molar conductivity of 0.5 M solution of the electrolyte in S m2 mol-1 is :
JEE Main 2014 (Offline)
88
Given

$$E_{C{r^{2 + }}/Cr}^o$$ = -0.74 V; $$E_{MnO_4^ - /M{n^{2 + }}}^o$$ = 1.51 V

$$E_{C{r_2}O_7^{2 - }/C{r^{3 + }}}^o$$ = 1.33 V; $$E_{Cl/C{l^ - }}^o$$ = 1.36 V

Based on the data given above, strongest oxidising agent will be :
JEE Main 2013 (Offline)
89
The standard reduction potentials for Zn2+/ Zn, Ni2+/ Ni, and Fe2+/ Fe are –0.76, –0.23 and –0.44 V respectively. The reaction

X + Y2+ $$\to$$ X2+ + Y will be spontaneous when :
AIEEE 2012
90
The reduction potential of hydrogen half cell will be negative if :
AIEEE 2011
91
The correct order of $$E_{{M^{2 + }}/M}^o$$ values with negative sign for the four successive elements Cr, Mn, Fe and Co is :
AIEEE 2010
92
The Gibbs energy for the decomposition of Al2O3 at 500oC is as follows :

$${2 \over 3}A{l_2}{O_3}$$ $$\to$$ $${4 \over 3}Al + {O_2}$$, $${\Delta _r}G$$ = + 966 kJ mol–1

The potential difference needed for electrolytic reduction of Al2O3 at 500oC is at least :
AIEEE 2010
93
Given : $$E_{F{e^{3 + }}/Fe}^o$$ = -0.036V; $$E_{F{e^{2 + }}/Fe}^o$$ = -0.439 V
The value of standard electrode potential for the change,
Fe3+ (aq) + e- $$\to$$ Fe2+ (aq) will be
AIEEE 2009
94
In a fuel cell methanol is used as fuel and oxygen gas is used as an oxidizer. The reaction is
CH3OH(l) + 3/2O2 $$\to$$ CO2 (g) + 2H2O (l)
At 298K standard Gibb’s energies of formation for CH3OH(l), H2O(l) and CO2 (g) are -166.2, -237.2 and -394.4 kJ mol−1 respectively. If standard enthalpy of combustion of methanol is -726 kJ mol−1, efficiency of the fuel cell will be
AIEEE 2009
95
Given $$E_{C{r^{3 + }}/Cr}^o$$ = -0.72 V; $$E_{Fe^{2+}/Fe}^o$$ = -0.42V, The potential for the cell Cr | Cr3+ (0.1M) || Fe2+ (0.01 M) | Fe is
AIEEE 2008
96
The equivalent conductances of two strong electrolytes at infinite dilution in H2O (where ions move freely through a solution) at 25oC are given below:
$$ \wedge _{C{H_3}COONa}^o$$ = 91.0 S cm2/equiv
$$ \wedge _{HCl}^o$$ = 426.2 S cm2/equiv
What additional information/quantity one needs to calculate $$ \wedge ^o$$ of an aqueous solution of acetic acid?
AIEEE 2007
97
The cell, Zn | Zn2+ (1M) || Cu2+ (1M) | Cu($$E_{cell}^o$$ = 1.10V) was allowed to be completely discharged at 298 K. The relative concentration of Zn2+ to Cu2+ $$\left[ {{{\left[ {Z{n^{2 + }}} \right]} \over {\left[ {C{u^{2 + }}} \right]}}} \right]$$ is
AIEEE 2007
98
The molar conductivities $$ \wedge _{NaOAc}^o$$ and $$ \wedge _{HCl}^o$$ and at infinite dilution in water at 25oC are 91.0 and 426.2 Scm2/mol respectively. To calculate $$ \wedge _{HOAc}^o$$ , the additional value required is
AIEEE 2006
99
Resistance of a conductivity cell filled with a solution of an electrolyte of concentration 0.1 M is 100$$\Omega $$. The conductivity of this solution is 1.29 S m–1. Resistance of the same cell when filled with 0.2 M of the same solution is 520 $$\Omega $$, The molar conductivity of 0.02 M solution of the electrolyte will be
AIEEE 2006
100
Given the data at 25oC,
Ag + I- $$\to$$ AgI + e- , Eo = 0.152 V
Ag $$\to$$ Ag+ + e-, Eo = -0.800 V
What is the value of log Ksp for AgI? (2.303 RT/F = 0.059 V)
AIEEE 2006
101
The highest electrical conductivity of the following aqueous solutions is of :
AIEEE 2005
102
Electrolyte: KCl KNO3 HCl NaOAc NaCl
$${ \wedge ^\infty }(Sc{m^2}mo{l^{ - 1}}):$$
149.9 145 426.2 91 126.5
Calculate $$ \wedge _{HOAc}^\infty $$ Using appropriate molar conductances of the electrolytes listed above at infinite dilution in H2O at 25oC
AIEEE 2005
103
Aluminium oxide may be electrolysed at 1000oC to furnish aluminium metal (Atomic mass = 27 amu; 1 Faraday = 96,500 Coulombs). The cathode reaction is Al3+ + 3e- $$\to$$ Alo To prepare 5.12 kg of aluminium metal by this method would require
AIEEE 2005
104
For a spontaneous reaction the ∆G , equilibrium constant (K) and $$E_{cell}^o$$ will be respectively
AIEEE 2005
105
In a hydrogen – oxygen fuel cell, combustion of hydrogen occurs to :
AIEEE 2004
106
Consider the following Eo values

$$E_{F{e^{3 + }}/F{e^{2 + }}}^o$$ = 0.77 V;

$$E_{S{n^{2 + }}/S{n}}^o$$ = -0.14 V

Under standard conditions the potential for the reaction

Sn(s) + 2Fe3+(aq) $$\to$$ 2Fe2+(aq) + Sn2+(aq) is :
AIEEE 2004
107
The standard e.m.f of a cell, involving one electron change is found to be 0.591 V at 25oC. The equilibrium constant of the reaction is (F = 96,500 C mol-1: R = 8.314 JK-1 mol-1)
AIEEE 2004
108
The limiting molar conductivities Λ° for NaCl, KBr and KCl are 126, 152 and 150 S cm2 mol-1 respectively. The Λ° for NaBr is
AIEEE 2004
109
In a cell that utilises the reaction Zn(s) + 2H+ (aq) $$\to$$ Zn2+(aq) + H2(g) addition of H2SO4 to cathode compartment, will
AIEEE 2004
110
The $$E_{{M^{3 + }}/{M^{2 + }}}^o$$ values for Cr, Mn, Fe and Co are – 0.41, +1.57, + 0.77 and +1.97 V respectively. For which one of these metals the change in oxidation state form +2 to +3 is easiest?
AIEEE 2004
111
Standard reduction electrode potentials of three metals A,B&C are respectively +0.5 V, -3.0 V & -1.2 V. The reducing, powers of these metals are
AIEEE 2003
112
When during electrolysis of a solution of AgNO3, 9650 coulombs of charge pass through the electroplating bath, the mass of silver deposited on the cathode will be :
AIEEE 2003
113
For the redox reaction Zn(s) + Cu2+(0.1 M) $$\to$$ Zn2+(1M) + Cu(s) taking place in a cell, $$E_{cell}^o$$ is 1.10 volt. Ecell for the cell will be ($$2.303{{RT} \over F}$$ = 0.0591)
AIEEE 2003
114
Several blocks of magnesium are fixed to the bottom of a ship to :
AIEEE 2003
115
For a cell reaction involving a two-electron change, the standard e.m.f. of the cell is found to be 0.295 V at 25oC. The equilibrium constant of the reaction at 25oC will be
AIEEE 2003
116
Conductivity (Seimen’s S) is directly proportional to area of the vessel and the concentration of the solution in it and is inversely proportional to the length of the vessel then, then constant of proportionality is expressed in :
AIEEE 2002
117
For the following cell with hydrogen electrodes at two different pressure p1 and p2. What will be the emf for the given cell :

$$\eqalign{ & Pt({H_2})|{H^ + }(aq)|Pt({H_2}) \cr & \,\,\,\,\,{p_1}\,\,\,\,\,\,\,\,\,\,\,\,\,\,1M\,\,\,\,\,\,\,\,\,\,\,\,{p_2} \cr} $$
AIEEE 2002
118
EMF of a cell in terms of reduction potential of its left and right electrodes is :
AIEEE 2002
119
Which of the following reaction is possible at anode?
AIEEE 2002
120
When the sample of copper with zinc impurity is to be purified by electrolysis, the appropriate electrodes are :
AIEEE 2002
121
For a cell given below

AIEEE 2002 Chemistry - Electrochemistry Question 46 English
$$ \begin{aligned} \mathrm{Ag}^{+}+\mathrm{e}^{-} & \longrightarrow \mathrm{Ag}; E^{\circ}=x \\\\ \mathrm{Cu}^{2+}+2 e^{-} & \longrightarrow \mathrm{Cu}{;} E^{\circ}=y \end{aligned} $$

$$ E^{\circ} \text { cell is } $$ :
AIEEE 2002

Numerical

1
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).
JEE Main 2025 (Online) 28th January Evening Shift
2

Given below is the plot of the molar conductivity vs $\sqrt{\text { concentration }}$ for KCl in aqueous solution.

JEE Main 2025 (Online) 28th January Morning Shift Chemistry - Electrochemistry Question 1 English

If, for the higher concentration of KCl solution, the resistance of the conductivity cell is $100 \Omega$, then the resistance of the same cell with the dilute solution is ' x ' $\Omega$

The value of $x$ is _________ (Nearest integer)

JEE Main 2025 (Online) 28th January Morning Shift
3

The standard reduction potentials at $$298 \mathrm{~K}$$ for the following half cells are given below :

$$\mathrm{Cr}_2 \mathrm{O}_7^{2-}+14 \mathrm{H}^{+}+6 \mathrm{e}^{-} \rightarrow 2 \mathrm{Cr}^{3+}+7 \mathrm{H}_2 \mathrm{O}, \quad \mathrm{E}^{\circ}=1.33 \mathrm{~V}$$

$$\begin{array}{ll} \mathrm{Fe}^{3+}(\mathrm{aq})+3 \mathrm{e}^{-} \rightarrow \mathrm{Fe} & \mathrm{E}^{\circ}=-0.04 \mathrm{~V} \\ \mathrm{Ni}^{2+}(\mathrm{aq})+2 \mathrm{e}^{-} \rightarrow \mathrm{Ni} & \mathrm{E}^{\circ}=-0.25 \mathrm{~V} \\ \mathrm{Ag}^{+}(\mathrm{aq})+\mathrm{e}^{-} \rightarrow \mathrm{Ag} & \mathrm{E}^{\circ}=0.80 \mathrm{~V} \\ \mathrm{Au}^{3+}(\mathrm{aq})+3 \mathrm{e}^{-} \rightarrow \mathrm{Au} & \mathrm{E}^{\circ}=1.40 \mathrm{~V} \end{array}$$

Consider the given electrochemical reactions,

The number of metal(s) which will be oxidized be $$\mathrm{Cr}_2 \mathrm{O}_7^{2-}$$, in aqueous solution is _________.

JEE Main 2024 (Online) 9th April Morning Shift
4
The amount of electricity in Coulomb required for the oxidation of $1 \mathrm{~mol}$ of $\mathrm{H}_2 \mathrm{O}$ to $\mathrm{O}_2$ is __________ $\times 10^5 \mathrm{C}$.
JEE Main 2024 (Online) 1st February Evening Shift
5
Consider the following redox reaction :

$$ \mathrm{MnO}_4^{-}+\mathrm{H}^{+}+\mathrm{H}_2 \mathrm{C}_2 \mathrm{O}_4 \rightleftharpoons \mathrm{Mn}^{2+}+\mathrm{H}_2 \mathrm{O}+\mathrm{CO}_2 $$

The standard reduction potentials are given as below $\left(\mathrm{E}_{\text {red }}^0\right)$ :

$$ \begin{aligned} & \mathrm{E}_{\mathrm{MnO}_4^{-} / \mathrm{Mn}^{2+}}^{\circ}=+1.51 \mathrm{~V} \\\\ & \mathrm{E}_{\mathrm{CO}_2 / \mathrm{H}_2 \mathrm{C}_2 \mathrm{O}_4}^{\circ}=-0.49 \mathrm{~V} \end{aligned} $$

If the equilibrium constant of the above reaction is given as $\mathrm{K}_{\mathrm{eq}}=10^x$, then the value of $x=$ __________ (nearest integer)
JEE Main 2024 (Online) 1st February Evening Shift
6
The potential for the given half cell at $298 \mathrm{~K}$ is (-) __________ $\times 10^{-2} \mathrm{~V}$

$$ \begin{aligned} & 2 \mathrm{H}_{(\mathrm{aq})}^{+}+2 \mathrm{e}^{-} \longrightarrow \mathrm{H}_2(\mathrm{~g}) \\\\ & {\left[\mathrm{H}^{+}\right]=1 \mathrm{M}, \mathrm{P}_{\mathrm{H}_2}=2 \mathrm{~atm}} \end{aligned} $$

(Given : $2.303 \mathrm{RT} / \mathrm{F}=0.06 \mathrm{~V}, \log 2=0.3$ )
JEE Main 2024 (Online) 1st February Morning Shift
7
The values of conductivity of some materials at $298.15 \mathrm{~K}^{-1} ~\text{in} ~\mathrm{Sm}^{-1}$ are $2.1 \times 10^3$,

$1.0 \times 10^{-16}, 1.2 \times 10,3.91,1.5 \times 10^{-2}, 1 \times 10^{-7}, 1.0 \times 10^3$.

The number of conductors among the materials is _____________.
JEE Main 2024 (Online) 31st January Evening Shift
8

Number of alkanes obtained on electrolysis of a mixture of $$\mathrm{CH}_3 \mathrm{COONa}$$ and $$\mathrm{C}_2 \mathrm{H}_5 \mathrm{COONa}$$ is ________.

JEE Main 2024 (Online) 31st January Morning Shift
9

One Faraday of electricity liberates $$x \times 10^{-1}$$ gram atom of copper from copper sulphate. $$x$$ is ________.

JEE Main 2024 (Online) 31st January Morning Shift
10

A constant current was passed through a solution of $$\mathrm{AuCl}_4^{-}$$ ion between gold electrodes. After a period of 10.0 minutes, the increase in mass of cathode was $$1.314 \mathrm{~g}$$. The total charge passed through the solution is _______ $$\times 10^{-2} \mathrm{~F}$$.

(Given atomic mass of $$\mathrm{Au}=197$$)

JEE Main 2024 (Online) 29th January Evening Shift
11

The mass of zinc produced by the electrolysis of zine sulphate solution with a steady current of $$0.015 \mathrm{~A}$$ for 15 minutes is _________ $$\times 10^{-4} \mathrm{~g}$$.

(Atomic mass of zinc $$=65.4 \mathrm{~amu}$$)

JEE Main 2024 (Online) 29th January Morning Shift
12

The hydrogen electrode is dipped in a solution of $$\mathrm{pH}=3$$ at $$25^{\circ} \mathrm{C}$$. The potential of the electrode will be _________ $$\times 10^{-2} \mathrm{~V}$$.

$$\left(\frac{2.303 \mathrm{RT}}{\mathrm{F}}=0.059 \mathrm{~V}\right)$$

JEE Main 2024 (Online) 27th January Evening Shift
13

The mass of silver (Molar mass of $$\mathrm{Ag}: 108 \mathrm{~gmol}^{-1}$$ ) displaced by a quantity of electricity which displaces $$5600 \mathrm{~mL}$$ of $$\mathrm{O}_2$$ at S.T.P. will be ______ g.

JEE Main 2024 (Online) 27th January Morning Shift
14
The number of correct statements from the following is _______.

(A) Conductivity always decreases with decrease in concentration for both strong and weak electrolytes.

(B) The number of ions per unit volume that carry current in a solution increases on dilution.

(C) Molar conductivity increases with decrease in concentration

(D) The variation in molar conductivity is different for strong and weak electrolytes

(E) For weak electrolytes, the change in molar conductivity with dilution is due to decrease in degree of dissociation.
JEE Main 2023 (Online) 15th April Morning Shift
15

At $$298 \mathrm{~K}$$, the standard reduction potential for $$\mathrm{Cu}^{2+} / \mathrm{Cu}$$ electrode is $$0.34 \mathrm{~V}$$.

Given : $$\mathrm{K}_{\mathrm{sp}} \mathrm{Cu}(\mathrm{OH})_{2}=1 \times 10^{-20}$$

Take $$\frac{2.303 \mathrm{RT}}{\mathrm{F}}=0.059 \mathrm{~V}$$

The reduction potential at $$\mathrm{pH}=14$$ for the above couple is $$(-) x \times 10^{-2} \mathrm{~V}$$. The value of $$x$$ is ___________

JEE Main 2023 (Online) 13th April Evening Shift
16

A metal surface of $$100 \mathrm{~cm}^{2}$$ area has to be coated with nickel layer of thickness $$0.001 \mathrm{~mm}$$. A current of $$2 \mathrm{~A}$$ was passed through a solution of $$\mathrm{Ni}\left(\mathrm{NO}_{3}\right)_{2}$$ for '$$\mathrm{x}$$' seconds to coat the desired layer. The value of $$\mathrm{x}$$ is __________. (Nearest integer) ( $$\rho_{\mathrm{Ni}}$$ (density of Nickel) is $$10 \mathrm{~g} \mathrm{~mL}$$, Molar mass of Nickel is $$60 \mathrm{~g} \mathrm{~mol}^{-1}$$ $$\left.\mathrm{F}=96500 ~\mathrm{C} ~\mathrm{mol}^{-1}\right)$$

JEE Main 2023 (Online) 13th April Morning Shift
17

The number of correct statements from the following is __________

A. $$\mathrm{E_{\text {cell }}}$$ is an intensive parameter

B. A negative $$\mathrm{E}^{\ominus}$$ means that the redox couple is a stronger reducing agent than the $$\mathrm{H}^{+} / \mathrm{H}_{2}$$ couple.

C. The amount of electricity required for oxidation or reduction depends on the stoichiometry of the electrode reaction.

D. The amount of chemical reaction which occurs at any electrode during electrolysis by a current is proportional to the quantity of electricity passed through the electrolyte.

JEE Main 2023 (Online) 11th April Evening Shift
18

In an electrochemical reaction of lead, at standard temperature, if $$\mathrm{E}^{0}\left(\mathrm{~Pb}^{2+} / \mathrm{Pb}\right)=\mathrm{m}$$ Volt and $$\mathrm{E}^{0}\left(\mathrm{~Pb}^{4+} / \mathrm{Pb}\right)=\mathrm{n}$$ Volt, then the value of $$\mathrm{E}^{0}\left(\mathrm{~Pb}^{2+} / \mathrm{Pb}^{4+}\right)$$ is given by $$\mathrm{m-x n}$$. The value of $$\mathrm{x}$$ is ___________. (Nearest integer)

JEE Main 2023 (Online) 11th April Morning Shift
19

The specific conductance of $$0.0025 ~\mathrm{M}$$ acetic acid is $$5 \times 10^{-5} \mathrm{~S} \mathrm{~cm}^{-1}$$ at a certain temperature. The dissociation constant of acetic acid is __________ $$\times ~10^{-7}$$ (Nearest integer)

Consider limiting molar conductivity of $$\mathrm{CH}_{3} \mathrm{COOH}$$ as $$400 \mathrm{~S} \mathrm{~cm}^{2} \mathrm{~mol}^{-1}$$

JEE Main 2023 (Online) 10th April Evening Shift
20

$$\mathrm{FeO_4^{2 - }\buildrel { + 2.2V} \over \longrightarrow F{e^{3 + }}\buildrel { + 0.70V} \over \longrightarrow F{e^{2 + }}\buildrel { - 0.45V} \over \longrightarrow F{e^0}}$$

$$E_{FeO_4^{2 - }/F{e^{2 + }}}^\theta $$ is $$x \times {10^{ - 3}}$$ V. The value of $$x$$ is _________

JEE Main 2023 (Online) 10th April Morning Shift
21

The number of incorrect statements from the following is ___________.

A. The electrical work that a reaction can perform at constant pressure and temperature is equal to the reaction Gibbs energy.

B. $$\mathrm{E_{cell}^{\circ}}$$ cell is dependent on the pressure.

C. $$\frac{d E^{\theta} \text { cell }}{\mathrm{dT}}=\frac{\Delta_{\mathrm{r}} \mathrm{S}^{\theta}}{\mathrm{nF}}$$

D. A cell is operating reversibly if the cell potential is exactly balanced by an opposing source of potential difference.

JEE Main 2023 (Online) 8th April Evening Shift
22

The standard reduction potentials at $$298 \mathrm{~K}$$ for the following half cells are given below:

$$\mathrm{NO}_{3}^{-}+4 \mathrm{H}^{+}+3 \mathrm{e}^{-} \rightarrow \mathrm{NO}(\mathrm{g})+2 \mathrm{H}_{2} \mathrm{O} \quad \mathrm{E}^{\theta}=0.97 \mathrm{~V}$$

$$\mathrm{V}^{2+}(\mathrm{aq})+2 \mathrm{e}^{-} \rightarrow \mathrm{V} \quad\quad\quad \mathrm{E}^{\theta}=-1.19 \mathrm{~V}$$

$$\mathrm{Fe}^{3+}(\mathrm{aq})+3 \mathrm{e}^{-} \rightarrow \mathrm{Fe} \quad\quad\quad \mathrm{E}^{\theta}=-0.04 \mathrm{~V}$$

$$\mathrm{Ag}^{+}(\mathrm{aq})+\mathrm{e}^{-} \rightarrow \mathrm{Ag}(\mathrm{s}) \quad\quad\quad \mathrm{E}^{\theta}=0.80 \mathrm{~V}$$

$$\mathrm{Au}^{3+}(\mathrm{aq})+3 \mathrm{e}^{-} \rightarrow \mathrm{Au}(\mathrm{s}) \quad\quad\quad \mathrm{E}^{\theta}=1.40 \mathrm{~V}$$

The number of metal(s) which will be oxidized by $$\mathrm{NO}_{3}^{-}$$ in aqueous solution is __________.

JEE Main 2023 (Online) 6th April Evening Shift
23

$$1 \times 10^{-5} ~\mathrm{M} ~\mathrm{AgNO}_{3}$$ is added to $$1 \mathrm{~L}$$ of saturated solution of $$\mathrm{AgBr}$$. The conductivity of this solution at $$298 \mathrm{~K}$$ is _____________ $$\times 10^{-8} \mathrm{~S} \mathrm{~m}^{-1}$$.

[Given : $$\mathrm{K}_{\mathrm{SP}}(\mathrm{AgBr})=4.9 \times 10^{-13}$$ at $$298 \mathrm{~K}$$

$$ \begin{aligned} & \lambda_{\mathrm{Ag}^{+}}^{0}=6 \times 10^{-3} \mathrm{~S} \mathrm{~m}^{2} \mathrm{~mol}^{-1} \\ & \lambda_{\mathrm{Br}^{-}}^{0}=8 \times 10^{-3} \mathrm{~S} \mathrm{~m}^{2} \mathrm{~mol}^{-1} \\ & \left.\lambda_{\mathrm{NO}_{3}^{-}}^{0}=7 \times 10^{-3} \mathrm{~S} \mathrm{~m}^{2} \mathrm{~mol}^{-1}\right] \end{aligned} $$

JEE Main 2023 (Online) 1st February Evening Shift
24

At what pH, given half cell $$\mathrm{MnO_{4}^{-}(0.1~M)~|~Mn^{2+}(0.001~M)}$$ will have electrode potential of 1.282 V? ___________ (Nearest Integer)

Given $$\mathrm{E_{MnO_4^ - |M{n^{2 + }}}^o}=1.54~\mathrm{V},\frac{2.303\mathrm{RT}}{\mathrm{F}}=0.059\mathrm{V}$$

JEE Main 2023 (Online) 1st February Morning Shift
25
The resistivity of a $0.8 \mathrm{M}$ solution of an electrolyte is $5 \times 10^{-3} \Omega~ \mathrm{cm}$.

Its molar conductivity is _________ $\times 10^{4}~ \Omega^{-1} \mathrm{~cm}^{2} \mathrm{~mol}^{-1}$. (Nearest integer)
JEE Main 2023 (Online) 31st January Evening Shift
26

The logarithm of equilibrium constant for the reaction $$\mathrm{Pd}^{2+}+4 \mathrm{Cl}^{-} \rightleftharpoons \mathrm{PdCl}_{4}^{2-}$$ is ___________ (Nearest integer)

Given : $$\frac{2.303 R \mathrm{~T}}{\mathrm{~F}}=0.06 \mathrm{~V}$$

$$ \mathrm{Pd}_{(\mathrm{aq})}^{2+}+2 \mathrm{e}^{-} \rightleftharpoons \mathrm{Pd}(\mathrm{s}) \quad \mathrm{E}^{\ominus}=0.83 \mathrm{~V} $$

$$ \begin{aligned} & \mathrm{PdCl}_{4}^{2-}(\mathrm{aq})+2 \mathrm{e}^{-} \rightleftharpoons \mathrm{Pd}(\mathrm{s})+4 \mathrm{Cl}^{-}(\mathrm{aq}) \mathrm{E}^{\ominus}=0.65 \mathrm{~V} \end{aligned} $$

JEE Main 2023 (Online) 31st January Morning Shift
27
The electrode potential of the following half cell at $298 \mathrm{~K}$

$\mathrm{X}\left|\mathrm{X}^{2+}(0.001 \mathrm{M}) \| \mathrm{Y}^{2+}(0.01 \mathrm{M})\right| \mathrm{Y}$ is _______ $\times 10^{-2} \mathrm{~V}$ (Nearest integer)

Given: $\mathrm{E}^{0} _ {\mathrm{X}^{2+} \mid \mathrm{X}}=-2.36 \mathrm{~V}$

$\mathrm{E}_{\mathrm{Y}^{2+} \mid \mathrm{Y}}^{0}=+0.36 \mathrm{~V}$

$\frac{2.303 \mathrm{RT}}{\mathrm{F}}=0.06 \mathrm{~V}$
JEE Main 2023 (Online) 30th January Evening Shift
28

Consider the cell

$$\mathrm{Pt}_{(\mathrm{s})}\left|\mathrm{H}_{2}(\mathrm{~g}, 1 \mathrm{~atm})\right| \mathrm{H}^{+}(\mathrm{aq}, 1 \mathrm{M})|| \mathrm{Fe}^{3+}(\mathrm{aq}), \mathrm{Fe}^{2+}(\mathrm{aq}) \mid \operatorname{Pt}(\mathrm{s})$$

When the potential of the cell is $$0.712 \mathrm{~V}$$ at $$298 \mathrm{~K}$$, the ratio $$\left[\mathrm{Fe}^{2+}\right] /\left[\mathrm{Fe}^{3+}\right]$$ is _____________. (Nearest integer)

Given : $$\mathrm{Fe}^{3+}+\mathrm{e}^{-}=\mathrm{Fe}^{2+}, \mathrm{E}^{\theta} \mathrm{Fe}^{3+}, \mathrm{Fe}^{2+} \mid \mathrm{Pt}=0.771$$

$$ \frac{2.303 \mathrm{RT}}{\mathrm{F}}=0.06 \mathrm{~V} $$

JEE Main 2023 (Online) 30th January Morning Shift
29

The equilibrium constant for the reaction

$$\mathrm{Zn(s)+Sn^{2+}(aq)}$$ $$\rightleftharpoons$$ $$\mathrm{Zn^{2+}(aq)+Sn(s)}$$ is $$1\times10^{20}$$ at 298 K. The magnitude of standard electrode potential of $$\mathrm{Sn/Sn^{2+}}$$ if $$\mathrm{E_{Z{n^{2 + }}/Zn}^\Theta = - 0.76~V}$$ is __________ $$\times 10^{-2}$$ V. (Nearest integer)

Given : $$\mathrm{\frac{2.303RT}{F}=0.059~V}$$

JEE Main 2023 (Online) 29th January Evening Shift
30

Following figure shows dependence of molar conductance of two electrolytes on concentration. $$\Lambda \mathop m\limits^o $$ is the limiting molar conductivity.

JEE Main 2023 (Online) 29th January Morning Shift Chemistry - Electrochemistry Question 64 English

The number of $$\mathrm{\underline {incorrect} }$$ statement(s) from the following is ___________

(A) $$\Lambda \mathop m\limits^o $$ for electrolyte A is obtained by extrapolation

(B) For electrolyte B, $$\Lambda \mathop m\limits $$ vs $$\sqrt c$$ graph is a straight line with intercept equal to $$\Lambda \mathop m\limits^o $$

(C) At infinite dilution, the value of degree of dissociation approaches zero for electrolyte B.

(D) $$\Lambda \mathop m\limits^o $$ for any electrolyte A and B can be calculated using $$\lambda^\circ$$ for individual ions

JEE Main 2023 (Online) 29th January Morning Shift
31

$$Pt(s)|{H_2}(g)(1\,bar)|{H^ + }(aq)(1\,M)||{M^{3 + }}(aq),{M^ + }(aq)|Pt(s)$$

The $$\mathrm{E_{cell}}$$ for the given cell is 0.1115 V at 298 K when $${{\left[ {{M^ + }(aq)} \right]} \over {\left[ {{M^{3 + }}(aq)} \right]}} = {10^a}$$

The value of $$a$$ is ____________

Given : $$\mathrm{E_{{M^{3 + }}/{M^ + }}^\theta = 0.2}$$ V

$${{2.303RT} \over F} = 0.059V$$

JEE Main 2023 (Online) 25th January Evening Shift
32

Consider the cell

$$\mathrm{Pt(s)|{H_2}(g)\,(1\,atm)|{H^ + }\,(aq,[{H^ + }] = 1)||F{e^{3 + }}(aq),F{e^{2 + }}(aq)|Pt(s)}$$

Given $$\mathrm{E_{F{e^{3 + }}/F{e^{2 + }}}^o = 0.771\,V}$$ and $$\mathrm{E_{{H^ + }/1/2\,{H_2}}^o = 0\,V,\,T = 298\,K}$$

If the potential of the cell is 0.712 V, the ratio of concentration of Fe$$^{2+}$$ to Fe$$^{3+}$$ is _____________ (Nearest integer)

JEE Main 2023 (Online) 25th January Morning Shift
33

At 298 K, a 1 litre solution containing 10 mmol of $$\mathrm{C{r_2}O_7^{2 - }}$$ and 100 mmol of $$\mathrm{Cr^{3+}}$$ shows a pH of 3.0.

Given : $$\mathrm{C{r_2}O_7^{2 - } \to C{r^{3 + }}\,;\,E^\circ = 1.330}$$V

and $$\mathrm{{{2.303\,RT} \over F} = 0.059}$$ V

The potential for the half cell reaction is $$x\times10^{-3}$$ V. The value of $$x$$ is __________

JEE Main 2023 (Online) 24th January Morning Shift
34

For a cell, $$\mathrm{Cu}(\mathrm{s})\left|\mathrm{Cu}^{2+}(0.001 \,\mathrm{M}) \| \mathrm{Ag}^{+}(0.01 \,\mathrm{M})\right| \mathrm{Ag}(\mathrm{s})$$

the cell potential is found to be $$0.43 \mathrm{~V}$$ at $$298 \mathrm{~K}$$. The magnitude of standard electrode potential for $$\mathrm{Cu}^{2+} / \mathrm{Cu}$$ is _________ $$\times 10^{-2} \mathrm{~V}$$.

[Given : $$E_{A{g^ + }/Ag}^\Theta $$ = 0.80 V and $${{2.303RT} \over F}$$ = 0.06 V]

JEE Main 2022 (Online) 29th July Evening Shift
35

Resistance of a conductivity cell (cell constant $$129 \mathrm{~m}^{-1}$$) filled with $$74.5 \,\mathrm{ppm}$$ solution of $$\mathrm{KCl}$$ is $$100 \,\Omega$$ (labelled as solution 1). When the same cell is filled with $$\mathrm{KCl}$$ solution of $$149 \,\mathrm{ppm}$$, the resistance is $$50 \,\Omega$$ (labelled as solution 2). The ratio of molar conductivity of solution 1 and solution 2 is i.e. $$\frac{\wedge_{1}}{\wedge_{2}}=x \times 10^{-3}$$. The value of $$x$$ is __________. (Nearest integer)

Given, molar mass of $$\mathrm{KCl}$$ is $$74.5 \mathrm{~g} \mathrm{~mol}^{-1}$$.

JEE Main 2022 (Online) 29th July Morning Shift
36

The amount of charge in $$\mathrm{F}$$ (Faraday) required to obtain one mole of iron from $$\mathrm{Fe}_{3} \mathrm{O}_{4}$$ is ___________. (Nearest Integer)

JEE Main 2022 (Online) 26th July Morning Shift
37

The spin-only magnetic moment value of M3+ ion (in gaseous state) from the pairs Cr3+ / Cr2+, Mn3+ / Mn2+, Fe3+ / Fe2+ and Co3+ / Co2+ that has negative standard electrode potential, is ____________ B.M. [Nearest integer]

JEE Main 2022 (Online) 25th July Evening Shift
38

The cell potential for $$\mathrm{Zn}\left|\mathrm{Zn}^{2+}(\mathrm{aq})\right|\left|\mathrm{Sn}^{x+}\right| \mathrm{Sn}$$ is $$0.801 \mathrm{~V}$$ at $$298 \mathrm{~K}$$. The reaction quotient for the above reaction is $$10^{-2}$$. The number of electrons involved in the given electrochemical cell reaction is ____________.

$$\left(\right.$$ Given $$: \mathrm{E}_{\mathrm{Zn}^{2+} \mid \mathrm{Zn}}^{\mathrm{o}}=-0.763 \mathrm{~V}, \mathrm{E}_{\mathrm{Sn}^{x+} \mid \mathrm{Sn}}^{\mathrm{o}}=+0.008 \mathrm{~V}$$ and $$\left.\frac{2.303 \mathrm{RT}}{\mathrm{F}}=0.06 \mathrm{~V}\right)$$

JEE Main 2022 (Online) 25th July Morning Shift
39

The cell potential for the given cell at 298 K

Pt| H2 (g, 1 bar) | H+ (aq) || Cu2+ (aq) | Cu(s)

is 0.31 V. The pH of the acidic solution is found to be 3, whereas the concentration of Cu2+ is 10$$-$$x M. The value of x is ___________.

(Given : $$E_{C{u^{2 + }}/Cu}^\Theta $$ = 0.34 V and $${{2.303\,RT} \over F}$$ = 0.06 V)

JEE Main 2022 (Online) 29th June Evening Shift
40

A dilute solution of sulphuric acid is electrolysed using a current of 0.10 A for 2 hours to produce hydrogen and oxygen gas. The total volume of gases produced a STP is _____________ cm3. (Nearest integer)

[Given : Faraday constant F = 96500 C mol$$-$$1 at STP, molar volume of an ideal gas is 22.7 L mol$$-$$1]

JEE Main 2022 (Online) 29th June Morning Shift
41

For the given reactions

Sn2+ + 2e$$-$$ $$\to$$ Sn

Sn4+ + 4e$$-$$ $$\to$$ Sn

the electrode potentials are ; $$E_{S{n^{2 + }}/Sn}^o = - 0.140$$ V and $$E_{S{n^{4 + }}/Sn}^o = + 0.010$$ V. The magnitude of standard electrode potential for $$S{n^{4 + }}/S{n^{2 + }}$$ i.e. $$E_{S{n^{4 + }}/S{n^{2 + }}}^o$$ is _____________ $$\times$$ 10$$-$$2 V. (Nearest integer)

JEE Main 2022 (Online) 28th June Evening Shift
42

The quantity of electricity in Faraday needed to reduce 1 mol of Cr2O$$_7^{2 - }$$ to Cr3+ is ____________.

JEE Main 2022 (Online) 28th June Morning Shift
43

For the reaction taking place in the cell :

Pt (s)| H2 (g)|H+(aq) || Ag+(aq) |Ag (s)

E$$_{cell}^o$$ = + 0.5332 V.

The value of $$\Delta$$fG$$^\circ$$ is ______________ kJ mol$$-$$1. (in nearest integer)

JEE Main 2022 (Online) 27th June Evening Shift
44

The limiting molar conductivities of NaI, NaNO3 and AgNO3 are 12.7, 12.0 and 13.3 mS m2 mol$$-$$1, respectively (all at 25$$^\circ$$C). The limiting molar conductivity of AgI at this temperature is ____________ mS m2 mol$$-$$1.

JEE Main 2022 (Online) 27th June Morning Shift
45

Cu(s) + Sn2+ (0.001M) $$\to$$ Cu2+ (0.01M) + Sn(s)

The Gibbs free energy change for the above reaction at 298 K is x $$\times$$ 10$$-$$1 kJ mol$$-$$1. The value of x is __________. [nearest integer]

[Given : $$E_{C{u^{2 + }}/Cu}^\Theta = 0.34\,V$$ ; $$E_{S{n^{2 + }}/Sn}^\Theta = - 0.14\,V$$ ; F = 96500 C mol$$-$$1]

JEE Main 2022 (Online) 26th June Evening Shift
46

A solution of Fe2(SO4)3 is electrolyzed for 'x' min with a current of 1.5 A to deposit 0.3482 g of Fe. The value of x is ___________. [nearest integer]

Given : 1 F = 96500 C mol$$-$$1

Atomic mass of Fe = 56 g mol$$-$$1

JEE Main 2022 (Online) 25th June Evening Shift
47

In a cell, the following reactions take place

$$\matrix{ {F{e^{2 + }} \to F{e^{3 + }} + {e^ - }} & {E_{F{e^{3 + }}/F{e^{2 + }}}^o = 0.77\,V} \cr {2{I^ - } \to {I_2} + 2{e^ - }} & {E_{{I_2}/{I^ - }}^o = 0.54\,V} \cr } $$

The standard electrode potential for the spontaneous reaction in the cell is x $$\times$$ 10$$-$$2 V 298 K. The value of x is ____________. (Nearest Integer)

JEE Main 2022 (Online) 25th June Morning Shift
48

The resistance of a conductivity cell containing 0.01 M KCl solution at 298 K is 1750 $$\Omega$$. If the conductivity of 0.01 M KCl solution at 298 K is 0.152 $$\times$$ 10$$-$$3 S cm$$-$$1, then the cell constant of the conductivity cell is ____________ $$\times$$ 10$$-$$3 cm$$-$$1.

JEE Main 2022 (Online) 24th June Evening Shift
49

The cell potential for the following cell

Pt |H2(g)|H+ (aq)|| Cu2+ (0.01 M)|Cu(s)

is 0.576 V at 298 K. The pH of the solution is __________. (Nearest integer)

(Given : $$E_{C{u^{2 + }}/Cu}^o = 0.34$$ V and $${{2.303\,RT} \over F} = 0.06$$ V)

JEE Main 2022 (Online) 24th June Morning Shift
50
If the conductivity of mercury at 0$$^\circ$$C is 1.07 $$\times$$ 106 S m$$-$$1 and the resistance of a cell containing mercury is 0.243$$\Omega$$, then the cell constant of the cell is x $$\times$$ 104 m$$-$$1. The value of x is ____________. (Nearest integer)
JEE Main 2021 (Online) 1st September Evening Shift
51
Consider the following cell reaction :

$$C{d_{(s)}} + H{g_2}S{O_{4(s)}} + {9 \over 5}{H_2}{O_{(l)}}$$ $$\rightleftharpoons$$ $$CdS{O_4}.{9 \over 5}{H_2}{O_{(s)}} + 2H{g_{(l)}}$$

The value of $$E_{cell}^0$$ is 4.315 V at 25$$^\circ$$C. If $$\Delta$$H$$^\circ$$ = $$-$$825.2 kJ mol$$-$$1, the standard entropy change $$\Delta$$S$$^\circ$$ in J K$$-$$1 is ___________. (Nearest integer) [Given : Faraday constant = 96487 C mol$$-$$1]
JEE Main 2021 (Online) 31st August Morning Shift
52
The resistance of a conductivity cell with cell constant 1.14 cm$$-$$1, containing 0.001 M KCl at 298 K is 1500 $$\Omega$$. The molar conductivity of 0.001 M KCl solution at 298 K in S cm2 mol$$-$$1 is ____________. (Integer answer)
JEE Main 2021 (Online) 27th August Evening Shift
53
For the galvanic cell,

Zn(s) + Cu2+ (0.02 M) $$\to$$ Zn2+ (0.04 M) + Cu(s),

Ecell = ______________ $$\times$$ 10$$-$$2 V. (Nearest integer)

[Use : $$E_{Cu/C{u^{2 + }}}^0$$ = $$-$$ 0.34 V, $$E_{Zn/Z{n^{2 + }}}^0$$ = + 0.76 V, $${{2.303RT} \over F} = 0.059\,V$$]
JEE Main 2021 (Online) 26th August Evening Shift
54
These are physical properties of an element

(A) Sublimation enthalpy

(B) Ionisation enthalpy

(C) Hydration enthalpy

(D) Electron gain enthalpy

The total number of above properties that affect the reduction potential is ____________ (Integer answer)
JEE Main 2021 (Online) 26th August Morning Shift
55
For the cell

Cu(s) | Cu2+ (aq) (0.1 M) || Ag+(aq) (0.01 M) | Ag(s)

the cell potential E1 = 0.3095 V

For the cell

Cu(s) | Cu2+ (aq) (0.01 M) || Ag+(aq) (0.001 M) | Ag(s)

the cell potential = ____________ $$\times$$ 10$$-$$2 V. (Round off the nearest integer).

[Use : $${{2.303RT} \over F}$$ = 0.059]
JEE Main 2021 (Online) 27th July Evening Shift
56
The conductivity of a weak acid HA of concentration 0.001 mol L$$-$$1 is 2.0 $$\times$$ 10$$-$$5 S cm$$-$$1. If $$\Lambda _m^o$$(HA) = 190 S cm2 mol$$-$$1, the ionization constant (Ka) of HA is equal to ______________ $$\times$$ 10$$-$$6. (Round off to the Nearest Integer)
JEE Main 2021 (Online) 27th July Morning Shift
57
Consider the cell at 25$$^\circ$$C

Zn | Zn2+ (aq), (1M) || Fe3+ (aq), Fe2+ (aq) | Pt(s)

The fraction of total iron present as Fe3+ ion at the cell potential of 1.500 V is x $$\times$$ 10$$-$$2. The value of x is ______________. (Nearest integer)

(Given : $$E_{F{e^{3 + }}/F{e^{2 + }}}^0 = 0.77V$$, $$E_{Z{n^{2 + }}/Zn}^0 = - 0.76V$$)
JEE Main 2021 (Online) 25th July Morning Shift
58
Assume a cell with the following reaction

$$C{u_{(s)}} + 2A{g^ + }(1 \times {10^{ - 3}}M) \to C{u^{2 + }}(0.250M) + 2A{g_{(s)}}$$

$$E_{cell}^\Theta = 2.97$$ V

Ecell for the above reaction is ______________ V. (Nearest integer)

[Given : log 2.5 = 0.3979, T = 298 K]
JEE Main 2021 (Online) 22th July Evening Shift
59
Potassium chlorate is prepared by electrolysis of KCl in basic solution as shown by following equation.

6OH$$-$$ + Cl$$-$$ $$\to$$ ClO3$$-$$ + 3H2O + 6e$$-$$

A current of xA has to be passed for 10h to produce 10.0g of potassium chlorate. The value of x is ____________. (Nearest integer)

(Molar mass of KClO3 = 122.6 g mol$$-$$1, F = 96500 C)
JEE Main 2021 (Online) 20th July Evening Shift
60
The molar conductivities at infinite dilution of barium chloride, sulphuric acid and hydrochloric acid are 280, 860 and 426 S cm2 mol$$-$$1 respectively. The molar conductivity at infinite dilution of barium sulphate is _________ S cm2 mol$$-$$1. (Round off to the Nearest Integer ).
JEE Main 2021 (Online) 18th March Evening Shift
61
For the reaction

2Fe3+(aq) + 2I$$-$$(aq) $$ \to $$ 2Fe2+(aq) + I2(s)

the magnitude of the standard molar Gibbs free energy change, $$\Delta$$rG$$_m^o$$ = $$-$$ ___________ kJ (Round off to the Nearest Integer).

$$\left[ {\matrix{ {E_{F{e^{2 + }}/Fe(s)}^o = - 0.440V;} & {E_{F{e^{3 + }}/Fe(s)}^o = - 0.036V} \cr {E_{{I_2}/2{I^ - }}^o = 0.539V;} & {F = 96500C} \cr } } \right]$$
JEE Main 2021 (Online) 18th March Morning Shift
62
A KCl solution of conductivity 0.14 S m$$-$$1 shows a resistance of 4.19$$\Omega$$ in a conductivity cell. If the same cell is filled with an HCl solution, the resistance drops to 1.03$$\Omega$$. The conductivity of the HCl solution is ____________ $$\times$$ 10$$-$$2 S m$$-$$1. (Round off to the Nearest Integer).
JEE Main 2021 (Online) 17th March Evening Shift
63
A 5.0 m mol dm$$-$$3 aqueous solution of KCl has a conductance of 0.55 mS when measured in a cell of cell constant 1.3 cm$$-$$1. The molar conductivity of this solution is ___________ mSm2 mol$$-$$1. (Round off to the Nearest Integer).
JEE Main 2021 (Online) 16th March Evening Shift
64
Emf of the following cell at 298K in V is x $$\times$$ 10$$-$$2.

Zn|Zn2+(0.1 M)||Ag+ (0.01 M)|Ag

The value of x is _________. (Rounded off to the nearest integer)

[Given : $$E_{Z{n^{2 + }}/Zn}^\theta = - 0.76V;E_{A{g^{2 + }}/Ag}^\theta = + 0.80V;{{2.303RT} \over F} = 0.059$$]
JEE Main 2021 (Online) 26th February Evening Shift
65
Consider the following reaction

$$MnO_4^ - + 8{H^ + } + 5{e^ - } \to M{n^{ + 2}} + 4{H_2}O,{E^o} = 1.51V$$.

The quantity of electricity required in Faraday to reduce five moles of $$MnO_4^ - $$ is ___________. (Integer answer)
JEE Main 2021 (Online) 26th February Morning Shift
66
Copper reduces NO$$_3^ - $$ into NO and NO2 depending upon the concentration of HNO3 in solution. (Assuming fixed [Cu2+] and PNO = PNO2), the HNO3 concentration at which the thermodynamic tendency for reduction of NO$$_3^ - $$ into NO and NO2 by copper is same is 10x M. The value of 2x is _______. (Rounded off to the nearest integer)

[Given, $$E_{C{u^{2 + }}/Cu}^o = 0.34$$ V, $$E_{NO_3^ - /NO}^o = 0.96$$ V, $$E_{NO_3^ - /N{O_2}}^o = 0.79$$ V and at 298 K, $${{RT} \over F}$$(2.303) = 0.059]
JEE Main 2021 (Online) 25th February Evening Shift
67
The magnitude of the change in oxidising power of the $$MnO_4^ - /M{n^{2 + }}$$ couple is x $$\times$$ 10$$-$$4 V, if the H+ concentration is decreased from 1M to 10$$-$$4 M at 25$$^\circ$$C. (Assume concentration of $$MnO_4^ - $$ and $$M{n^{2 + }}$$ to be same on change in H+ concentration). The value of x is ___________. $$\left[ {Given\,:{{2.303RT} \over F} = 0.059} \right]$$
JEE Main 2021 (Online) 24th February Evening Shift
68
Potassium chlorate is prepared by the electrolysis of KCl in basic solution

6OH- + Cl- $$ \to $$ ClO3- + 3H2O + 6e-

If only 60% of the current is utilized in the reaction, the time (rounded to the nearest hour) required to produce 10 g of KClO3 using a current of 2 A is_________.

(Given : F = 96,500 C mol–1; molar mass of KCIO3 = 122 g mol–1)
JEE Main 2020 (Online) 6th September Morning Slot
69
An oxidation-reduction reaction in which
3 electrons are transferred has a $$\Delta $$Gº of 17.37 kJ mol–1 at
25 oC. The value of Eo
cell (in V) is ______ × 10–2.
(1 F = 96,500 C mol–1)
JEE Main 2020 (Online) 5th September Morning Slot
70
An acidic solution of dichromate is electrolyzed for 8 minutes using 2A current. As per the following equation
Cr2O72- + 14H+ + 6e $$ \to $$ 2Cr3+ + 7H2O
The amount of Cr3+ obtained was 0.104 g. The efficiency of the process(in%) is (Take : F = 96000 C, At. mass of chromium = 52) ______.
JEE Main 2020 (Online) 3rd September Evening Slot
71
The photoelectric current from Na (Work function, w0 = 2.3 eV) is stopped by the output voltage of the cell
Pt(s) | H2 (g, 1 Bar) | HCl (aq., pH =1) | AgCl(s) | Ag(s).
The pH of aq. HCl required to stop the photoelectric current form K(w0 = 2.25 eV), all other conditions remaining the same, is _______ $$ \times $$ 10-2 (to the nearest integer).

Given, 2.303$${{RT} \over F}$$ = 0.06 V;
$$E_{AgCl|Ag|C{l^ - }}^0$$ = 0.22 V
JEE Main 2020 (Online) 3rd September Morning Slot
72
For the disproportionation reaction
2Cu+(aq) ⇌ Cu(s) + Cu2+(aq) at 298 K. ln K
(where K is the equilibrium constant) is
___________ × 10–1.
Given :
($$E_{C{u^{2 + }}/C{u^ + }}^0 = 0.16V$$
$$E_{C{u^ + }/Cu}^0 = 0.52V$$
$${{RT} \over F} = 0.025$$)
JEE Main 2020 (Online) 2nd September Evening Slot
73
The Gibbs change (in J) for the given reaction at
[Cu2+] = [Sn2+] = 1 M and 298K is :

Cu(s) + Sn2+(aq.) $$ \to $$ Cu2+(aq.) + Sn(s);

($$E_{S{n^{2 + }}|Sn}^0 = - 0.16\,V$$,
$$E_{C{u^{2 + }}|Cu}^0 = 0.34\,V$$)
Take F = 96500 C mol–1)
JEE Main 2020 (Online) 2nd September Morning Slot
74
108 g of silver (molar mass 108 g mol–1) is deposited at cathode from AgNO3(aq) solution by a 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 _______.
JEE Main 2020 (Online) 9th January Morning Slot
75
For an electrochemical cell

Sn(s) | Sn2+ (aq,1M)||Pb2+ (aq,1M)|Pb(s)

the ratio $${{\left[ {S{n^{2 + }}} \right]} \over {\left[ {P{b^{2 + }}} \right]}}$$ when this cell attains equilibrium is _________.

(Given $$E_{S{n^{2 + }}|Sn}^0 = - 0.14V$$,

$$E_{P{b^{2 + }}|Pb}^0 = - 0.13V$$, $${{2.303RT} \over F} = 0.06$$)
JEE Main 2020 (Online) 8th January Evening Slot
76
What would be the electrode potential for the given half cell reaction at pH = 5? ______.

2H2O $$ \to $$ O2 + 4H$$ \oplus $$ + 4e ; $$E_{red}^0$$ = 1.23 V

(R = 8.314 J mol–1 K–1 ; Temp = 298 k;

oxygen under std. atm. pressure of 1 bar)
JEE Main 2020 (Online) 8th January Morning Slot
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