Question

In a cell, the following reactions take place

${\mathrm{Fe}}^{2+}\to {\mathrm{Fe}}^{3+}+{\mathrm{e}}^{-} {{\mathrm{E}}^{\mathrm{o}}}_{{\mathrm{Fe}}^{3+}/{\mathrm{Fe}}^{2+}}=0.77 \mathrm{V}$

$2{\mathrm{I}}^{-}\to {\mathrm{I}}_2+2{\mathrm{e}}^{-} {\mathrm{E}}_{{\mathrm{I}}_2/{\mathrm{I}}^{-}}^0=0.54 \mathrm{V}$

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

JEE Main 2022 (25 Jun Shift 1)

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Question

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 (15 Apr Shift 1)

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Question

For the disproportionation reaction $2{\mathrm{Cu}}^{+}\left(\mathrm{aq}\right)\rightleftharpoons \mathrm{Cu}\left(\mathrm{s}\right)+{\mathrm{Cu}}^{2+}\left(\mathrm{aq}\right)$ at $298\mathrm{K},$$\ln \mathrm{K}$  (where $\mathrm{K}$ is the equilibrium constant) is _______$\times {10}^{-1}$

Given $:\left(\mathrm{E}{°}_{{\mathrm{Cu}}^{2+}/{\mathrm{Cu}}^{+}}=0.16V E{°}_{{\mathrm{Cu}}^{+}/\mathrm{Cu}}=0.52\mathrm{V}\frac{\mathrm{RT}}{\mathrm{F}}=0.025\right)$

JEE Main 2020 (02 Sep Shift 2)

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Question

The conductivity of a weak acid$\mathrm{HA}$ of concentration $0.001 \mathrm{mol}{ \mathrm{L}}^{-1}$ is $2.0\times {10}^{-5} \mathrm{S}{ \mathrm{cm}}^{-1}$. If ${\Lambda }_{\mathrm{m}}^0\left(\mathrm{HA}\right)=190 \mathrm{S}{ \mathrm{cm}}^2{ \mathrm{mol}}^{-1},$ the ionization constant $\left({\mathrm{K}}_{\mathrm{a}}\right)$ of HA is equal to $\_\_\_\_$ $\times {10}^{-6}$
(Round off to the Nearest Integer)

JEE Main 2021 (27 Jul Shift 1)

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Question

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 ; ${\mathrm{E}}_{{\mathrm{Sn}}^{2+}/\mathrm{Sn}}^{°}=-0.140 \mathrm{V}$ and ${\mathrm{E}}_{{\mathrm{Sn}}^{4+}/\mathrm{Sn}}^{°}=0.010 \mathrm{V}$. The magnitude of standard electrode potential for ${\mathrm{Sn}}^{4+}/{\mathrm{Sn}}^{2+}$ i.e. ${\mathrm{E}}_{{\mathrm{Sn}}^{4+}/{\mathrm{Sn}}^{2+}}^{°}$ is____$\times {10}^{-2} \mathrm{V}$(Nearest integer)

JEE Main 2022 (28 Jun Shift 2)

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Question

Match List I with List II \(\begin{array}{|l|l|l|l|} \hline & \text{ List - I (Cell) } & & \text{List - II (Use/Property/Reaction)} \\ \hline \text { A. } & \text { Leclanche cell } & \text { I. } & \begin{array}{l} \text { Converts energy of combustion into electrical } \\ \text { energy } \end{array} \\ \hline \text { B. } & \mathrm{Ni}-\mathrm{Cd} \text { cell } & \text { II. } & \begin{array}{l} \text { Does not involve any ion in solution and is used } \\ \text { in hearing aids } \end{array} \\ \hline \text { C. } & \text { Fuel cell } & \text { III. } & \text { Rechargeable } \\ \hline \text { D. } & \text { Mercury cell } & \text { IV. } & \text { Reaction at anode } \mathrm{Zn} \rightarrow \mathrm{Zn}^{2+}+2 \mathrm{e}^{-} \\ \hline \end{array}\) Choose the correct answer from the options given below:

JEE Main 2024 (09 Apr Shift 2)

Options

• A: A-II, B-III, C-IV, D-I
• B: A-I, B-II, C-III, D-IV
• C: A-III, B-I, C-IV, D-II
• D: A-IV, B-III, C-I, D-II

Question

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

JEE Main 2024 (05 Apr Shift 1)

Options

• A: reduction of \(\mathrm{Mn}\) from +7 to +2
• B: reduction of \(\mathrm{Mn}\) from +4 to +3
• C: oxidation of \(\mathrm{Mn}\) from +3 to +4
• D: oxidation of \(\mathrm{Mn}\) from +2 to +7

Question

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

JEE Main 2024 (31 Jan Shift 1)

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Question

For the cell $\mathrm{Cu}\left(\mathrm{s}\right)\left|{\mathrm{Cu}}^{2+}\left(\mathrm{aq}\right)(0.1\mathrm{M})\Vert {\mathrm{Ag}}^{+}\left(\mathrm{aq}\right)(0.01\mathrm{M})\right|\mathrm{Ag}\left(\mathrm{s}\right)$ the cell potential ${\mathrm{E}}_1=0.3095 \mathrm{V}$. For the cell $\mathrm{Cu}\left(\mathrm{s}\right)\left|{\mathrm{Cu}}^{2+}\left(\mathrm{aq}\right)(0.01\mathrm{M})\Vert {\mathrm{Ag}}^{+}\left(\mathrm{aq}\right)(0.001\mathrm{M})\right|\mathrm{Ag}\left(\mathrm{s}\right)$ the cell potential $=\mathrm{x}\times {10}^{-2} \mathrm{V}.$ Find value of x (Round off the Nearest Integer).

[ Use $:\frac{2.303\mathrm{RT}}{\mathrm{F}}=0.059 \mathrm{J}$ ]

JEE Main 2021 (27 Jul Shift 2)

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Question

Match List-I with List-II.

Choose the correct answer from the options given below

JEE Main 2022 (28 Jul Shift 1)

Options

• A: $\mathrm{A}-\mathrm{I},\mathrm{B}-\mathrm{II},\mathrm{C}-\mathrm{III},\mathrm{C}-\mathrm{IV}$
• B: $\mathrm{A}-\mathrm{IV},\mathrm{B}-\mathrm{I},\mathrm{C}-\mathrm{IV},\mathrm{C}-\mathrm{III}$
• C: $\mathrm{A}-\mathrm{II},\mathrm{B}-\mathrm{I},\mathrm{C}-\mathrm{IV},\mathrm{C}-\mathrm{III}$
• D: $\mathrm{A}-\mathrm{II},\mathrm{B}-\mathrm{I},\mathrm{C}-\mathrm{III},\mathrm{C}-\mathrm{IV}$

Question

A solution of ${\mathrm{Fe}}_2{\left({\mathrm{SO}}_4\right)}_3$ is electrolyzed for '$\mathrm{x}$' min with a current of $1.5 \mathrm{A}$ to deposit $0.3482 \mathrm{g}$ of $\mathrm{Fe}$. The value of $\mathrm{x}$ is - [nearest integer]

Given : $1 \mathrm{F}=96500 {\mathrm{Cmol}}^{-1}$. Atomic mass of $\mathrm{Fe}=56 {\mathrm{gmol}}^{-1}$

JEE Main 2022 (25 Jun Shift 2)

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Question

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

JEE Main 2024 (05 Apr Shift 2)

Options

• A: \(1 \mathrm{~g}\) of silver
• B: 1 electrochemical equivalent of silver
• C: 1 chemical equivalent of silver
• D: \(0.1 \mathrm{~g}\) atom of silver

Question

The limiting molar conductivities of $\mathrm{NaI},{\mathrm{NaNO}}_3$ and ${\mathrm{AgNO}}_3$ are $12.7,12.0$ and $13.3 {\mathrm{mSm}}^2{ \mathrm{mol}}^{-1}$, respectively (all at $25 °\mathrm{C}$). The limiting molar conductivity of $\mathrm{AgI}$ at this temperature is____${\mathrm{mSm}}^2{ \mathrm{mol}}^{-1}$.

JEE Main 2022 (27 Jun Shift 1)

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Question

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 (08 Apr Shift 2)

Options

• A: \(\mathrm{Ag}\left|\mathrm{AgCl}_{(\text {s) }}\right| \mathrm{KCl}_{\text {(soln.) }}\left|\mathrm{AgNO}_{3 \text { (aq.) }}\right| \mathrm{Ag}\)
• B: \(\mathrm{Pt}\left|\mathrm{H}_{2(\mathrm{~g})}\right| \mathrm{HCl}_{\text {(soln.) }}\left|\mathrm{AgCl}_{(\mathrm{s})}\right| \mathrm{Ag}\)
• C: \(\mathrm{Pt}\left|\mathrm{H}_{2(\mathrm{~g})}\right| \mathrm{KCl}_{(\text {soln. })}\left|\mathrm{AgCl}_{(s)}\right| \mathrm{Ag}\)
• D: \(\mathrm{Pt}\left|\mathrm{H}_{2(\mathrm{~g})}\right| \mathrm{HCl}_{\text {(soln.) }}\left|\mathrm{AgNO}_{3(\mathrm{aq})}\right| \mathrm{Ag}\)

Question

The potential for the given half cell at $298\mathrm{K}$ is $\left(-\right)$............ $\times {10}^{-2}\mathrm{V}.$

$2{\mathrm{H}}_{\left(\mathrm{aq}\right)}^{+}+2{\mathrm{e}}^{-}\to {\mathrm{H}}_2( \mathrm{g})$

$\left[{\mathrm{H}}^{+}\right]=1\mathrm{M},{\mathrm{P}}_{{\mathrm{H}}_2}=2 \mathrm{atm}$

(Given$2.303 \mathrm{RT}/\mathrm{F}=0.06 \mathrm{V}, \log 2=0.3$)

JEE Main 2024 (01 Feb Shift 1)

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Question

The resistance of a conductivity cell containing $0.01 \mathrm{MKCl}$ solution at $298 \mathrm{K}$ is $1750 \mathrm{\Omega }$. If the conductivity of $0.01 \mathrm{MKCl}$ solution at $298 \mathrm{K}$
is $0.152\times {10}^{-3} \mathrm{S}{ \mathrm{cm}}^{-1}$, then the cell constant of the conductivity cell is____$\times {10}^{-3}{ \mathrm{cm}}^{-1}$

JEE Main 2022 (24 Jun Shift 2)

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Question

The cell potential for the given cell at $298 \mathrm{K} \mathrm{Pt}\left|{\mathrm{H}}_2\left(\mathrm{g},1 \mathrm{bar}\right)\right|\left|{\mathrm{H}}^{+}\left(\mathrm{aq}\right)\Vert {\mathrm{Cu}}^{2+}\left(\mathrm{aq}\right)\right|\mathrm{Cu}\left(\mathrm{s}\right)$ is $0.31 \mathrm{V}$. The $\mathrm{pH}$ of the acidic solution is found to be $3$, whereas the concentration of ${\mathrm{Cu}}^{2+}$ is ${10}^{\mathrm{x}} \mathrm{M}$. The value of $\mathrm{x}$ is _________.

(Given: ${\mathrm{E}}_{{\mathrm{Cu}}^{2+}/\mathrm{Cu}}^{\Theta }=0.34 \mathrm{V}$ and $\frac{2.303\mathrm{RT}}{\mathrm{F}}=0.06 \mathrm{V}$)

JEE Main 2022 (29 Jun Shift 2)

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Question

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

JEE Main 2023 (06 Apr Shift 1)

Options

• A: Hydration of a gaseous metal ion
• B:

  Sublimation of a solid metal

• C: Ionisation of a solid metal atom
• D: Ionisation of a gaseous metal atom

Question

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 $~38\%$ solution of sulphuric acid as an electrolyte

Choose the correct answer from the options given below:

JEE Main 2023 (12 Apr Shift 1)

Options

• A: A, B, D only
• B: B, C, D only
• C: B, C only
• D: B, D only

Question

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 $\left({\mathrm{E}}_{\mathrm{red}}°\right)$

${{\mathrm{E}}^0}_{{\mathrm{MnO}}_4^{-}/{\mathrm{Mn}}^{2+}}=+1.51 \mathrm{V}$;  ${{\mathrm{E}}^0}_{{\mathrm{CO}}_2/{\mathrm{H}}_2{\mathrm{C}}_2{\mathrm{O}}_4}=-0.49 \mathrm{V}$

If the equilibrium constant of the above reaction is given as ${\mathrm{K}}_{\mathrm{eq}}={10}^{\mathrm{x}}$, then the value of $\mathrm{x}=$ _______ (nearest integer)

JEE Main 2024 (01 Feb Shift 2)

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