Redox Reactions and Electrochemistry — JEE Main PYQs

40 mL of a mixture of ${\mathrm{CH}}_3\mathrm{COOH}$ and HCl (aqueous solution) is titrated against 0.1 M NaOH solution conductometrically. Which of the following statement is correct?

The standard cell potential $({\mathrm{E}}_{\text{cell}}^{\ominus })$ of a fuel cell based on the oxidation of methanol in air that has been used to power television relay station is measured as 1.21 V. The standard half cell reduction potential for ${\mathrm{O}}_2$ …

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

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

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 aluminium as catalysts
D. is eco-friendly
E. is actually a type of Galvanic cell only

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

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

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

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

For the electro chemical cell
$\mathrm{M}\left|{\mathrm{M}}^{2+}\Vert \mathrm{X}\right|{\mathrm{X}}^{2-}$
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 …

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 -

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

Match List-I with the List-II

List-I (Reaction)

(A) ${\mathrm{N}}_{2(\mathrm{g})}+{\mathrm{O}}_{2(\mathrm{g})}\to 2{\mathrm{NO}}_{(\mathrm{g})}$

(B) …

The emf of cell $\mathrm{T}1\left|\underset{(0.001\mathrm{M})}{\mathrm{T}{1}^{+}}\right|\underset{(0.01\mathrm{M})}{{\mathrm{Cu}}^{2+}}\mid \mathrm{Cu}$ is 0.83 V at 298 K . It could be increased by :

The reaction ;

occurs in which of the following galvanic cell :

Thiosulphate reacts differently with iodine and bromine in the reaction given below :
$2{\mathrm{S}}_2{\mathrm{O}}_3^{2-}+{\mathrm{I}}_2\to {\mathrm{S}}_4{\mathrm{O}}_6^{2-}+2{\mathrm{I}}^{-}$ …

Iron (III) catalyses the reaction between iodide and persulphate ions, in which
A. ${\mathrm{Fe}}^{3+}$ oxidises the iodide ion
B. ${\mathrm{Fe}}^{3+}$ oxidises the persulphate ion
C. ${\mathrm{Fe}}^{2+}$ reduces the iodide ion
D. ${\mathrm{Fe}}^{2+}$ reduces the persulphate ion …

The molar conductivity for electrolytes A and B are plotted against ${\mathrm{C}}^{1/2}$ as shown below. Electrolytes A and B respectively are :

Given below are two statements :

Statement (I) : The oxidation state of an element in a particular compound is the charge acquired by its atom on the basis of electron gain enthalpy consideration from other atoms in the molecule.
Statement (II) : …

The standard reduction potentials at 298 K for the following half cells are given below :
${\mathrm{Cr}}_2{\mathrm{O}}_7{}^{2-}+14{\mathrm{H}}^{+}+6{\mathrm{e}}^{-}\to 2{\mathrm{Cr}}^{3+}+7{\mathrm{H}}_2\mathrm{O},{\mathrm{E}}^{\circ }=1.33\mathrm{V}$ …

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 :

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

The amount of electricity in Coulomb required for the oxidation of 1 mol of ${\mathrm{H}}_2\mathrm{O}$ to ${\mathrm{O}}_2$ is ____ $\times 10^5\mathrm{C}$.

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 ( …

In acidic medium, ${\mathrm{K}}_2{\mathrm{Cr}}_2{\mathrm{O}}_7$ shows oxidising action as represented in the half reaction
${\mathrm{Cr}}_2{\mathrm{O}}_7^{2-}+{\mathrm{XH}}^{+}+{\mathrm{Ye}}^{-}\to 2\mathrm{A}+{\mathrm{ZH}}_2\mathrm{O}$ …

Which of the following reactions are disproportionation reactions?
(A) ${\mathrm{Cu}}^{+}\to {\mathrm{Cu}}^{2+}+\mathrm{Cu}$
(B) $3{\mathrm{MnO}}_4^{2-}+4{\mathrm{H}}^{+}\to 2{\mathrm{MnO}}_4^{-}+{\mathrm{MnO}}_2+2{\mathrm{H}}_2\mathrm{O}$
(C) …

The potential for the given half cell at 298 K is
(-) ____ $\times 10^{-2}$ V.
$2{\mathrm{H}}_{(\mathrm{aq})}^{+}+2{\mathrm{e}}^{-}\to {\mathrm{H}}_2(\mathrm{g})$
$[{\mathrm{H}}^{+}]=1$ M, ${\mathrm{P}}_{{\mathrm{H}}_2}=2$ atm
(Given: 2.303 RT/F=0.06 V, $\log 2=0.3$)

Lowest Oxidation number of an atom in a compound ${\mathrm{A}}_2\mathrm{B}$ is -2. The number of an electron in its valence shell is

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

Which of the following cannot function as an oxidising agent?

1 mole of PbS is oxidised by "X" moles of ${\mathrm{O}}_3$ to get "Y" moles of ${\mathrm{O}}_2$. $\mathrm{X}+\mathrm{Y}=$ $\_\_\_\_$

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

Chlorine undergoes disproportionation in alkaline medium as shown below :
a …

In alkaline medium. ${\mathrm{MnO}}_4^{-}$oxidises ${\mathrm{I}}^{-}$to

The mass of zinc produced by the electrolysis of zinc sulphate solution with a steady current of 0.015 A for 15 minutes is ____ $\times 10^{-4}\mathrm{g}$.
$($ Atomic mass of zinc $=65.4\mathrm{amu})$

The oxidation number of iron in the compound formed during brown ring test for ${\mathrm{NO}}_3^{-}$ion is ____.

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 g. The total charge passed through the solution is _____ $\times 10^{-2}\text{ F}$.
(Given atomic mass of …

The metals that are employed in the battery industries are
A. Fe
B. Mn
C. Ni
D. Cr
E. Cd

Choose the correct answer from the options given below:

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

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

0.05 cm thick coating of silver is deposited on a plate of $0.05{\mathrm{m}}^2$ area. The number of silver atoms deposited on plate are ______ $\times 10^{23}$. (At mass Ag = 108, $\mathrm{d}=7.9{\mathrm{g}\mathrm{cm}}^{-3}$)

$2{\mathrm{MnO}}_4^{-}+\mathrm{b}{\mathrm{I}}^{-}+\mathrm{c}{\mathrm{H}}_2\mathrm{O}\to \mathrm{x}{\mathrm{I}}_2+\mathrm{y}{\mathrm{MnO}}_2+\mathrm{z}{\mathrm{OH}}^{-}$

If the above equation is balanced with integer coefficients, the value of z is ______

Number of moles of ${\mathrm{H}}^{+}$ ions required by 1 mole of ${\mathrm{MnO}}_4^{-}$ to oxidise oxalate ion to ${\mathrm{CO}}_2$ is ____.

Reduction potential of ions are given below:


The correct orde …

Total number of species from the following which can undergo disproportionation reaction ____.
${\mathrm{H}}_2{\mathrm{O}}_2,{\mathrm{ClO}}_3^{-},{\mathrm{P}}_4,{\mathrm{Cl}}_2,\mathrm{Ag},{\mathrm{Cu}}^{+1},{\mathrm{F}}_2,{\mathrm{NO}}_2,{\mathrm{K}}^{+}$

Match List I with List II:
List-I (Cell): A. Leclanché cell B. Ni-Cd cell C. Fuel cell D. Mercury cell
List-II (Use/Property/Reaction): I. Converts energy of combustion into electrical energy II. Does not involve any ion in solution and is used in hearing aids III. Recharg …

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

Which of the following options are correct for the reaction
$2[\mathrm{Au}(\mathrm{CN}{)}_2{]}_{(\mathrm{aq})}^{-}+\mathrm{Zn}(\mathrm{s})\to 2\mathrm{Au}(\mathrm{s})+[\mathrm{Zn}(\mathrm{CN}{)}_4{]}_{(\mathrm{aq})}^{2-}$
A. Redox reaction
B. Displacement reaction
C. Decomp …

In ammonium-phosphomolybdate, the oxidation state of Mo is ${}^{+}$ ______

During the reaction of permanganate with thiosulphate, the change in oxidation of manganese occurs by value of 3. Identify which of the below medium will favour the reaction.