Redox Reactions and Electrochemistry — JEE Main PYQs

The product, which is not obtained during the electrolysis of brine solution is

The standard reduction potential at 298 K for the following half cells are given below:-
${\mathrm{NO}}_3^{-}+4{\mathrm{H}}^{+}+3{\mathrm{e}}^{-}\to \mathrm{NO}(\mathrm{g})+2{\mathrm{H}}_2\mathrm{O}{\mathrm{E}}^0=0.97\mathrm{V}$ …

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. ${\mathrm{E}}_{\text{cell }}^0$ is dependent on the pressure
C. …

In alkaline medium, the reduction of permanganate anion involves a gain of ______ electrons.

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

Consider limiting molar conductivity of …

$2{\mathrm{IO}}_3^{-}+{\mathrm{xI}}^{-}+12{\mathrm{H}}^{+}\to 6{\mathrm{I}}_2+6{\mathrm{H}}_2\mathrm{O}$

What is the value of x ?

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.

${\mathrm{FeO}}_4^{2-}\stackrel{+2.2\mathrm{V}}{\to }{\mathrm{Fe}}^{3+}\stackrel{+0.70\mathrm{V}}{\to }{\mathrm{Fe}}^{2+}\stackrel{-0.45\mathrm{V}}{\to }{\mathrm{Fe}}^0$

${\mathrm{E}}_{{\mathrm{FeO}}_4^{2-}/{\mathrm{Fe}}^{2+}}^{\theta }$ is $\mathrm{x}\times 10^{-3}\mathrm{V}$. T …

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

The number of correct statements from the following is :
(A) ${\mathrm{E}}_{\text{cell}}$ is an intensive parameter.
(B) A negative ${\mathrm{E}}^{\Theta }$ means that the redox couple is a stronger reducing agent than the ${\mathrm{H}}^{+}/{\mathrm{H}}_2$ couple.
(C) The amount of el …

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 …

${\mathrm{KMnO}}_4$ is titrated with ferrous ammonium sulphate hexahydrate in presence of dilute ${\mathrm{H}}_2{\mathrm{SO}}_4$. Number of water molecules produced for 2 molecules of ${\mathrm{KMnO}}_4$ is $\_\_\_\_$.

A metal surface of $100{\mathrm{cm}}^2$ area has to be coated with nickel layer of thickness 0.001 mm. A current of 2 A was passed through a solution of $\mathrm{Ni}{\left({\mathrm{NO}}_3\right)}_2$ for '$x$' seconds to coat the desired layer. The value of $x$ is $\_\_\_\_$ (Ne …

The correct group of halide ions which can be oxidised by oxygen in acidic medium is

See the following chemical reaction:
${\mathrm{Cr}}_2{\mathrm{O}}_7^{2-}+X{\mathrm{H}}^{+}+6{\mathrm{Fe}}^{2+}\to Y{\mathrm{Cr}}^{3+}+6{\mathrm{Fe}}^{3+}+Z{\mathrm{H}}_2\mathrm{O}$
The sum of X, Y and Z is ______.

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

The total change in the oxidation state of manganese involved in the reaction of ${\mathrm{KMnO}}_4$ and potassium iodide in the acidic medium is ____

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 conductiv …

At what pH , given half cell ${\mathrm{MnO}}_4^{-}(0.1\mathrm{M})\mid {\mathrm{Mn}}^{2+}(0.001\mathrm{M})$ will have electrode potential of 1.282 V ?
____ (Nearest Integer)

Given …

At 298 K, a 1 litre solution containing 10 mmol of ${\mathrm{Cr}}_2{\mathrm{O}}_7{}^{2-}$ and 100 mmol of ${\mathrm{Cr}}^{3+}$ shows a pH of 3.0.

Given : ${\mathrm{Cr}}_2{\mathrm{O}}_7{}^{2-}\to {\mathrm{Cr}}^{3+}$ ; ${\mathrm{E}}^0=1.330\mathrm{V}$ and …

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

Consider the cell


Given: …

$\mathrm{Pt}(\mathrm{s}){\mathrm{H}}_2(\mathrm{g})(1\mathrm{bar})\left|{\mathrm{H}}^{+}(\mathrm{aq})(1\mathrm{M})\right|\left|{\mathrm{M}}^{3+}(\mathrm{aq}),{\mathrm{M}}^{+}(\mathrm{aq})\right|\mathrm{Pt}(\mathrm{s})$

The ${\mathrm{E}}_{\text{cell }}$ for the given cell …

The standard electrode potential ( ${\mathrm{M}}^{3+}/{\mathrm{M}}^{2+}$ ) for V , $\mathrm{Cr}$, $\mathrm{Mn}$ & $\mathrm{Co}$ are $-0.26\mathrm{V}$, $-0.41\mathrm{V}$, $+1.57\mathrm{V}$ and $+1.97\mathrm{V}$ , respectively. The metal ions which can liberate …

Following figure shows dependence of molar conductance of two electrolytes on concentration. ${\Lambda }_{\mathrm{m}}^0$ is the limiting molar conductivity.

The number of Incorrect statement(s) from the following is ______
(A) ${\Lambda }_{\mathrm{m}}^0$ for electrolyte A is obtai …

The equilibrium constant for the reaction
$\mathrm{Zn}(\mathrm{s})+\mathrm{Sn}{}^{2+}(\mathrm{aq})\rightleftharpoons \mathrm{Zn}{}^{2+}(\mathrm{aq})+\mathrm{Sn}(\mathrm{s})$ is $1\times 10^{20}$ at 298 K. The magnitude of standard electrode potential of $\mathrm{Sn}/\mathrm{Sn}{}^{2+}$ if $E_{\mathrm{Zn}{}^{2+}/\mathrm{Zn}}^{\mathrm{o}}=-0.76\mathrm{V}$ is
$\_\_\_\_$ …

Consider the cell
${\mathrm{Pt}}_{(\mathrm{s})}\left|{\mathrm{H}}_2(\mathrm{g},1\mathrm{atm})\right|{\mathrm{H}}^{+}(\mathrm{aq},1\mathrm{M})||{\mathrm{Fe}}^{3+}(\mathrm{aq}),{\mathrm{Fe}}^{2+}(\mathrm{aq})\mid \mathrm{Pt}(\mathrm{s})$
When the potential of the cell is 0.712 …

$1\times 10^{-5}$ M ${\mathrm{AgNO}}_3$ is added to 1 L of saturated solution of AgBr. The conductivity of this solution at 298 K is ______ $\times 10^{-8}{\mathrm{S}\mathrm{m}}^{-1}$.
[Given: $K_{\mathrm{sp}}(\mathrm{AgBr})=4.9\times 10^{-13}$ at 298 K, …

The resistivity of a 0.8 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)

The electrode potential of the following half cell at 298 K.
$\mathrm{X}|{\mathrm{X}}^{2+}(0.001\mathrm{M})||{\mathrm{Y}}^{2+}(0.01\mathrm{M})|\mathrm{Y}$ is ______ $\times 10^{-2}\mathrm{V}$ (Nearest integer).

Given: …

When ${\mathrm{Cu}}^{2+}$ ion is treated with KI , a white precipitate, X appears in solution. The solution is titrated with sodium thiosulphate, the compound Y is formed. X and Y respectively are

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

The logarithm of equilibrium constant for the reaction ${\mathrm{Pd}}^{2+}+4{\mathrm{Cl}}^{-}\rightleftharpoons {\mathrm{PdCl}}_4^{2-}$ is ______ (Nearest integer)

Given: $\frac{2.303RT}{F}=0.06\mathrm{V}$ …

For a cell, $\mathrm{Cu}(\mathrm{s})\mid {\mathrm{Cu}}^{2+}(0.001\mathrm{M})\mid \mid {\mathrm{Ag}}^{+}(0.01\mathrm{M})\mid \mathrm{Ag}(\mathrm{s})$ the cell potential is found to be 0.43 V at 298 K. The magnitude of standard electrode potential for …

Which of the following has least tendency to liberate ${\mathrm{H}}_2$ from mineral acids?

On reaction with stronger oxidizing agent like ${\mathrm{KIO}}_4$, hydrogen peroxide oxidizes with the evolution of ${\mathrm{O}}_2$. The oxidation number of I in ${\mathrm{KIO}}_4$ changes to ____.

20 mL of $0.02\mathrm{M}{\mathrm{K}}_2{\mathrm{Cr}}_2{\mathrm{O}}_7$ solution is used for the titration of 10 mL of ${\mathrm{Fe}}^{2+}$ solution in the acidic medium.

The molarity of ${\mathrm{Fe}}^{2+}$ solution is $\_\_\_\_$ $\times 10^{-2}\mathrm{M}$.
(Nearest Integer)

In the titration of ${\mathrm{KMnO}}_4$ and oxalic acid in acidic medium, the change in oxidation number of carbon at the end point is ____

The reaction of ${\mathrm{H}}_2{\mathrm{O}}_2$ with potassium permanganate in acidic medium leads to the formation of mainly:

The cell potential for Zn|Zn²⁺(aq)||Snˣ⁺|Sn is 0.801 V at 298 K. The reaction quotient for the above reaction is 10⁻². The number of electrons involved in the given electrochemical cell reaction is......
(Given E°_Zn²⁺|Zn = -0.763 V, E°_Snˣ⁺|Sn = +0.008 V and (2.303RT)/F = 0.06 V …

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 bel …

The molar conductivity of a conductivity cell filled with 10 moles of 20 mL NaCl solution is ${\Lambda }_{\mathrm{m}1}$ and that of 20 moles another identical cell heaving 80 mL NaCl solution is ${\Lambda }_{\mathrm{m}2}$, The conductivities exhibited by these two cells are same. …

Which of the given reactions is not an example of disproportionation reaction?

At 298 K, the equilibrium constant is $2\times 10^{15}$ for the reaction:
$\mathrm{Cu}(\mathrm{s})+2{\mathrm{Ag}}^{+}(\mathrm{aq})\rightleftharpoons {\mathrm{Cu}}^{2+}(\mathrm{aq})+2\mathrm{Ag}(\mathrm{s})$
The equilibrium constant for the reaction …

The amount of charge in F (Faraday) required to obtain one mole of iron from ${\mathrm{Fe}}_3{\mathrm{O}}_4$ is ______.
(Nearest Integer)

For the given reactions
${\mathrm{Sn}}^{2+}+2{\mathrm{e}}^{-}\to \mathrm{Sn}$
${\mathrm{Sn}}^{4+}+4{\mathrm{e}}^{-}\to \mathrm{Sn}$
The electrode potentials are; ${\mathrm{E}}_{{\mathrm{Sn}}^{2+}/\mathrm{Sn}}^{\mathrm{o}}=-0.140\mathrm{V}$ and …

$0.01$ M $\mathrm{KMnO}{}_4$ solution was added to 20.0 mL of 0.05 M Mohr's salt solution through a burette. The initial reading of 50 mL burette is zero. The volume of $\mathrm{KMnO}{}_4$ solution left in the burette after the end point is ______ mL. (nearest integer)

In 3d series, the metal having the highest ${\mathrm{M}}^{2+}/\mathrm{M}$ standard electrode potential is

For the reaction taking place in the cell:
$\mathrm{Pt}(\mathrm{s})|{\mathrm{H}}_2(\mathrm{g})|{\mathrm{H}}^{+}(\mathrm{aq})||{\mathrm{Ag}}^{+}(\mathrm{aq})|\mathrm{Ag}(\mathrm{s})$ ${\mathrm{E}}_{\text{Cell}}^{\circ }=+0.5332\mathrm{V}$.
The value of …

A 2.0 g sample containing $\mathrm{MnO}{}_2$ is treated with HCl liberating $\mathrm{Cl}{}_2$. The $\mathrm{Cl}{}_2$ gas is passed into a solution of KI and 60.0 mL of 0.1 M $\mathrm{Na}{}_2\mathrm{S}{}_2\mathrm{O}{}_3$ is required to titrate the liberated iodine. The percentage of $\mathrm{MnO}{}_2$ in the sample is ______.
(Nearest int …