Electrochemistry

Given at 298 K :
$$ \begin{aligned} & \mathrm{E}_{\mathrm{Fe}^{2+} / \mathrm{Fe}}^{\ominus}=\mathrm{X} \text { Volt } \\ & \mathrm{E}_{\mathrm{Fe}^{3+} / \mathrm{Fe}}^{\ominus}=\mathrm{Y} \text { Volt } \end{aligned} $$
The $\mathrm{E}_{\ma...

\(\text { Consider the following data. }\)
$$ \begin{array}{|c|c|} \hline \text { Electrolyte } & \wedge^{\circ}_\mathbf{m}{\mathbf{(}} \mathbf{S ~ c m}^{\mathbf{2}} \mathbf{~ m o l}^{\mathbf{1}} \mathbf{)} \\ \hline \mathrm{BaCl}_2 & x_1...

For a general redox reaction
Anode $\quad \operatorname{Red}_1 \rightarrow \mathrm{Ox}_1^{\mathrm{n}_1^{+}}+\mathrm{n}_1 \mathrm{e}^{-}$
Cathode $\mathrm{O} x_2+\mathrm{n}_2 \mathrm{e}^{-} \rightarrow \operatorname{Red}_2^{\mathrm{n}_2-}$
W...

At 298 K , the molar conductivity of $x \%(\mathrm{w} / \mathrm{w}) \mathrm{MX}$ solution (aqueous) is $123.5 \mathrm{~S} \mathrm{~cm}^2 \mathrm{~mol}^{-1}$. The conductance of same solution is $1.9 \times 10^{-3} \mathrm{~S}$. The value of...

One half cell in a voltaic cell is constructed by dipping silver rod in $\mathrm{AgNO}_3$ solution of unknown concentration, other half cell is Zn rod dipped in 1 molar solution of $\mathrm{ZnSO}_4$.
A voltage of 1.60 V is measured at 298 K...

An electrochemical cell, consist of the following two redox couples, $\mathrm{M}^{x+} (\mathrm{aq}) / \mathrm{M}(\mathrm{s})\left[\mathrm{E}_{\text {red }}^{\Theta}=+0.15 \mathrm{~V}\right]$ and $\mathrm{Fe}^{3+}(\mathrm{aq}) / \mathrm{Fe}(...

An electrochemical cell is constructed using half cells in the direction of spontaneous change:Fe(OH)2(s) + 2e− → Fe(s) + 2OH−(aq)      Eθ = −0.88 Vand AgBr(s) + e− → Ag(s) + Br−(aq)      Eθ = +0.07 VWhich of the following option is correct...

Consider the following two half-cell reactions along with the standard reduction potential given :
$\mathrm{CO}_2 + 6\mathrm{H}^+ + 6e^- \longrightarrow \mathrm{CH}_3\mathrm{OH} + \mathrm{H}_2\mathrm{O}\qquad E_{\text{red}}^{\circ} = 0.02\ ...

Consider the following redox reaction taking place in acidic medium
\(\mathrm{BH}_4^{-}(a q)+\mathrm{ClO}_3^{-}(a q) \longrightarrow \mathrm{H}_2 \mathrm{BO}_3^{-}(a q)+\mathrm{Cl}^{-}(a q)\)
If the Nernst equation for the above balanced ...

For strong electrolyte $\Lambda_m$ increases slowly with dilution and can be represented by the equation\(\Lambda_m = \Lambda_m^\circ - A c^{1/2}\)Molar conductivity values of the solutions of strong electrolyte AB at 18°C are given below :...

A volume of x mL of 5 M NaHCO3 solution was mixed with 10 mL of 2 M H2CO3 solution to make an electrolytic buffer. If the same buffer was used in the following electrochemical cell to record a cell potential of 235.3 mV, then the value of x...

Electricity is passed through an acidic solution of $\mathrm{Cu}^{2+}$ till all the $\mathrm{Cu}^{2+}$ was exhausted, leading to the deposition of 300 mg of Cu metal. However, a current of 600 mA was continued to pass through the same solut...

Molar conductivity of a weak acid HQ of concentration 0.18 M was found to be $1 / 30$ of the molar conductivity of another weak acid HZ with concentration of 0.02 M . If $\lambda^{\circ} \mathrm{Q}^{-}$happened to be equal with $\lambda^{\c...

In the given electrochemical cell, $\mathrm{Ag}(\mathrm{s})|\mathrm{AgCl}(\mathrm{s})| \mathrm{FeCl}_2(\mathrm{aq}), \mathrm{FeCl}_3(\mathrm{aq}) \mid \mathrm{Pt}(\mathrm{s})$ at 298 K , the cell potential ( $\mathrm{E}_{\text {cell }}$ ) w...

Consider the above electrochemical cell where a metal electrode ( M ) is undergoing redox reaction by forming $\mathrm{M}^{+}\left(\mathrm{M} \rightarrow \mathrm{M}^{+}+\mathrm{e}^{-}\right)$. The cation $\mathrm{M}^{+}$is present in two d...

Consider the following electrochemical cell at 298 K
$\mathrm{Pt}\left|\mathrm{HSnO}_2^{-}(\mathrm{aq})\right| \mathrm{Sn}(\mathrm{OH})_6{ }^{2-}(\mathrm{aq})\left|\mathrm{OH}^{-}(\mathrm{aq})\right| \mathrm{Bi}_2 \mathrm{O}_3(\mathrm{~s}) ...

Consider the following electrochemical cell :
\(\mathrm{Pt}\left|\mathrm{O}_2(\mathrm{~g})(1 \mathrm{bar})\right| \mathrm{HCl}(\mathrm{aq}) \| \mathrm{M}^{2+}(\mathrm{aq}, 1.0 \mathrm{M}) \mid \mathrm{M}(\mathrm{~s})\)
The pH above which,...

Consider the following reduction processes :
$$ \begin{aligned} & \mathrm{Al}^{3+}+3 \mathrm{e}^{-} \longrightarrow \mathrm{Al}(\mathrm{~s}), \mathrm{E}^0=-1.66 \mathrm{~V} \\ & \mathrm{Fe}^{3+}+\mathrm{e}^{-} \longrightarrow \mathrm{Fe}^{2...

The pH and conductance of a weak acid $(\mathrm{HX})$ was found to be 5 and $4 \times 10^{-5} \mathrm{~S}$, respectively. The conductance was measured under standard condition using a cell where the electrode plates having a surface area of...

MX is a sparingly soluble salt that follows the given solubility equilibrium at 298 K.
$\mathrm{MX}(\mathrm{s}) \rightleftharpoons \mathrm{M}^{+}(\mathrm{aq})+\mathrm{X}^{-}(\mathrm{aq}) ; \quad \mathrm{K}_{\mathrm{sp}}=10^{-10}$
If the sta...

For a closed circuit Daniell cell, which of the following plots is the accurate one at a given temperature?

Consider the following half cell reaction\(\text{Cr}_2\text{O}_7^{2-} \, (\text{aq}) + 6\text{e}^- + 14\text{H}^+ \, (\text{aq}) \rightarrow 2\text{Cr}^{3+} \, (\text{aq}) + 7\text{H}_2\text{O} \, (\ell)\)The reaction was conducted with ...

1 Faraday electricity was passed through $\mathrm{Cu}^{2+}(1.5 \mathrm{M}, 1 \mathrm{~L}) / \mathrm{Cu}$ and 0.1 Faraday was passed through $\mathrm{Ag}^{+}(0.2 \mathrm{M}, 1 \mathrm{~L}) / \mathrm{Ag}$ electrolytic cells. After this the tw...

Given below are two statements : 1 M aqueous solutions of each of Cu(NO3)2, AgNO3, Hg2(NO3)2, Mg(NO3)2 are electrolysed using inert electrodes. Given: E0Ag+/Ag = 0.80 V, E0Hg22+/Hg = 0.79 V, E0Cu2+/Cu = 0.24 V and E0Mg2+/Mg = -2.37 V.Statem...

On charging the lead storage battery, the oxidation state of lead changes from $x_1$ to $y_1$ at the anode and from $x_2$ to $y_2$ at the cathode. The values of $x_1, y_1, x_2, y_2$ are respectively :

Correct order of limiting molar conductivity for cations in water at 298 K is :

The standard cell potential $\left(\mathrm{E}_{\text {cell }}^{\ominus}\right)$ 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 red...

Consider the following electrochemical cell at standard condition.
$$\mathrm{Au}(\mathrm{~s})\left|\mathrm{QH}_2, \mathrm{Q}\right| \mathrm{NH}_4 \mathrm{X}(0.01 \mathrm{M})| | \mathrm{Ag}^{+}(1 \mathrm{M}) \mid \mathrm{Ag}(\mathrm{~s}) \ma...

$0.2 \%(\mathrm{w} / \mathrm{v})$ solution of NaOH is measured to have resistivity $870.0 \mathrm{~m} \Omega \mathrm{~m}$. The molar conductivity of the solution will be__________$\times 10^2 \mathrm{mS} \mathrm{dm}^2 \mathrm{~mol}^{-1}$. (...

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

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?

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

$\mathrm{O}_2$ 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 $\ma...

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
...

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

If, for the higher concentration of KCl solution, the resistance of the conductivity cell is $100 \Omega$, then the resistan...

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).

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}
\mathr...

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{Mn...

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


In the above diagram, the standard electrode potentials are given in vol...

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} \\
& \m...

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}^{-...

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

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...

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

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 \ma...

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 :

Match List I with List II

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...

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 alkalin...

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 :

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 :