jee main chemistry important questions | Electrochemistry jee main questions FREE

Q 1 :

One of the commonly used electrodes is calomel electrode. Under which of the following categories calomel electrode come? [2024]

Metal ion – Metal electrodes
Oxidation – Reduction electrodes
Metal – Insoluble Salt – Anion electrodes
Gas – Ion electrodes

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(3)

Calomel electrode is a metal-metal insoluble salt-anion half cell. It is commonly used as a reference like standard hydrogen electrode.

Q 2 :

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

Reversing the flow of ions in salt bridge.
Applying an external opposite potential greater than $E_{cell}^{0}$ .
Exchanging the electrodes at anode and cathode.
Applying an external opposite potential lower than $E_{cell}^{0}$ .

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(2)

When in an electrochemical cell, external voltage greater than $E_{cell}^{\circ}$ is applied, then direction of flow of charge is reversed. Now external source supplies energy to the cell and cell is now electrolytic cell.

Q 3 :

Reduction potential of ions are given below:

${ClO}_{4}^{-}$ ${IO}_{4}^{-}$ ${BrO}_{4}^{-}$

$E^{°} = 1.19 V$ $E^{°} = 1.65 V$ $E^{°} = 1.74 V$

The correct order of their oxidising power is: [2024]

${ClO}_{4}^{-} > {IO}_{4}^{-} > {BrO}_{4}^{-}$
${BrO}_{4}^{-} > {IO}_{4}^{-} > {ClO}_{4}^{-}$
${BrO}_{4}^{-} > {ClO}_{4}^{-} > {IO}_{4}^{-}$
${IO}_{4}^{-} > {BrO}_{4}^{-} > {ClO}_{4}^{-}$

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(2)

Oxidising power $\propto$ reduction potential.

So more is reduction potential of a specie, more is its ability to oxidize the other substance.

$\to_{Decreasing oxidising power}^{{BrO}_{4}^{-} (E ° = 1.74 V) > {IO}_{4}^{-} (E ° = 1.65 V) > {ClO}_{4}^{-} (E ° = 1.19 V)}$

Q 4 :

Match List I with List II.

List I List II

(Cell) (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 $Zn \to {Zn}^{2 +} + 2 e^{-}$

Choose the correct answer from the options given below: [2024]

A–II, B–III, C–IV, D–I
A–III, B–I, C–IV, D–II
A–I, B–II, C–III, D–IV
A–IV, B–III, C–I, D–II

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(4)

A. Leclanche cell: It is commonly used dry cell in our clocks. The cell consists of a zinc container that also acts as anode and the cathode is a carbon (graphite) rod surrounded by powdered manganese dioxide and carbon. The space between the electrodes is filled by a moist paste of ammonium chloride and zinc chloride.

Anode reaction: $Zn(s) \to {Zn}^{2 +} + 2 e^{-}$

Cathode reaction: ${MnO}_{2} + {NH}_{4}^{+} + e^{-} \to MnO (OH) + {NH}_{3}$

B. Ni-Cd cell: It is a rechargeable cell. It is more expensive to manufacture than a lead storage battery.

$Cd(s) + 2 {Ni(OH)}_{3} (s) \to CdO(s) + 2 {Ni(OH)}_{2} (s) + H_{2} O(l)$

C. Fuel cell: These are galvanic cells that are designed to convert the energy of combustion of fuels like hydrogen, methane, methanol, etc., directly into electrical energy.

D. Mercury cell:

$Zn(Hg) + HgO(s) \to ZnO(s) + Hg(l)$

The cell potential is approximately 1.35 V and remains constant during its life as the overall reaction does not involve any ion in solution whose concentration can change during its lifetime.

Q 5 :

The standard reduction potentials at 298 K for the following half cells are given below: [2024]

$C r_{2} O_{7}^{2 -} + 14 H^{+} + 6 e^{-} \to 2 C r^{3 +} + 7 H_{2} O, E^{0} = 1.33 V$

$F e^{3 +} (a q) + 3 e^{-} \to F e, E^{0} = - 0.04 V$

$N i^{2 +} (a q) + 2 e^{-} \to N i, E^{0} = - 0.25 V$

$A g^{+} (a q) + e^{-} \to A g, E^{0} = 0.80 V$

$A u^{3 +} (a q) + 3 e^{-} \to A u, E^{0} = 1.40 V$

Consider the given electrochemical reactions,

The number of metal(s) which will be oxidized be $C r_{2} O_{7}^{2 -}$ in aqueous solution is __________.

(3)

For the above reaction to be spontaneous:

$E_{r e a c t i o n}^{o} = E_{c a t h o d e}^{o} - E_{a n o d e}^{o} > 0$

$E_{C r_{2} O_{7}^{2 -}}^{o} - E_{a n o d e}^{o} > 0$

$1.33 - E_{a n o d e}^{o} > 0$

$E_{a n o d e}^{o} < 1.33 V$

Thus Fe, Ni and Ag will be oxidized by $C r_{2} O_{7}^{2 -}$ .

Q 6 :

${FeO}_{4}^{2 -} \overset{+ 2.0 V}{\to} {Fe}^{3 +} \overset{0.8 V}{\to} {Fe}^{2 +} \overset{- 0.5 V}{\to} {Fe}^{0}$

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

The value of $E_{{FeO}_{4}^{2 -} / {Fe}^{2 +}}^{⊝}$ is [2025]

2.1 V
1.7 V
1.2 V
1.4 V

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(2)

When two reactions are added their Gibbs energy change is added, as Gibbs energy change is an extensive property.

$Δ G_{4}^{\circ} = Δ G_{1}^{\circ} + Δ G_{2}^{\circ}$

$- n_{4} F E_{4}^{\circ} = - n_{1} F E_{1}^{\circ} - n_{2} F E_{2}^{\circ}$

$- 4 F E_{4}^{\circ} = - 3 F \times 2 - 1 F \times 0.8$

$E_{4}^{\circ} = \frac{6.8}{4} V = 1.7 V$

Q 7 :

For the given cell

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

The standard cell potential of the above reaction is:

Given:

${Ag}^{+} + e^{-} \to Ag$ $E^{θ} = x V$

${Fe}^{2 +} + 2 e^{-} \to Fe$ $E^{θ} = y V$

${Fe}^{3 +} + 3 e^{-} \to Fe$ $E^{θ} = z V$ [2025]

$x + 2 y - 3 z$
$x + 2 y$
$x + y - z$
$y - 2 x$

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(1)

${Ag}^{+} + e^{-} \to Ag-I (Δ G_{1} = - n F E_{1} = - 1 F x)$

${Fe}^{2 +} + 2 e^{-} \to Fe-II (Δ G_{2} = - n F E_{2} = - 2 F y)$

${Fe}^{3 +} + 3 e^{-} \to Fe-III (Δ G_{3} = - n F E_{3} = - 3 F z)$

$I + II - III$ gives the required equation:

${Fe}^{2 +} + {Ag}^{+} \to {Fe}^{3 +} + Ag-IV$

$Δ G_{4} = Δ G_{1} + Δ G_{2} - Δ G_{3} = - 1 F x - 2 F y + 3 F z$

$- n F E_{4} = - 1 F x - 2 F y + 3 F z$

$- I F E_{4} = - 1 F x - 2 F y + 3 F z$

$E_{4} = x + 2 y - 3 z$

Q 8 :

Based on the data given below:

$E_{{Cr}_{2} O_{7}^{2 -} / {Cr}^{3 +}}^{\circ} = 1.33 V E_{{Cl}_{2} / {Cl}^{-}}^{\circ} = 1.36 V$

$E_{{MnO}_{4}^{-} / {Mn}^{2 +}}^{\circ} = 1.51 V E_{{Cr}^{3 +} / Cr}^{\circ} = - 0.74 V$

The strongest reducing agent is: [2025]

${Mn}^{2 +}$
${Cl}^{-}$
${MnO}_{4}^{-}$
$Cr$

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(4)

Strongest reducing agent is the specie which has highest tendency to get oxidized i.e. the one with highest oxidation potential.

Reduction potential	Oxidation potential
$E_{{Cr}_{2} O_{7}^{2 -} / {Cr}^{3 +}}^{\circ} = 1.33 V$	$E_{{Cr}^{3 +} / {Cr}_{2} O_{7}^{2 -}}^{\circ} = - 1.33 V$
$E_{{Cl}_{2} / {Cl}^{-}}^{\circ} = 1.36 V$	$E_{{Cl}^{-} / {Cl}_{2}}^{\circ} = - 1.36 V$
$E_{{MnO}_{4}^{-} / {Mn}^{2 +}}^{\circ} = 1.51 V$	$E_{{Mn}^{2 +} / {MnO}_{4}^{-}}^{\circ} = - 1.51 V$
$E_{{Cr}^{3 +} / Cr}^{\circ} = - 0.74 V$	$E_{Cr / {Cr}^{3 +}}^{\circ} = 0.74 V$

Q 9 :

The standard reduction potential values of some of the $p$ -block ions are given below. Predict the one with the strongest oxidising capacity. [2025]

$E_{{Sn}^{4 +} / {Sn}^{2 +}}^{⊝} = + 1.15 V$
$E_{{Pb}^{4 +} / {Pb}^{2 +}}^{⊝} = + 1.67 V$
$E_{{Tl}^{3 +} / Tl}^{⊝} = + 1.26 V$
$E_{{Al}^{3 +} / Al}^{⊝} = - 1.66 V$

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(2)

Specie with highest reduction potential (i.e. highest willingness to get reduced) is strongest oxidizing agent.

Q 10 :

The standard electrode potential $(M^{3 +} / M^{2 +})$ for V, Cr, Mn and Co are - 0.26 V, - 0.41 V, + 1.57 V and + 1.97 V, respectively. The metal ions which can liberate $H_{2}$ from a dilute acid are [2023]

$V^{2 +}$ and ${Mn}^{2 +}$
${Mn}^{2 +}$ and ${Co}^{2 +}$
${Cr}^{2 +}$ and ${Co}^{2 +}$
$V^{2 +}$ and ${Cr}^{2 +}$

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(4)

The metal ion for which have less value of reduction potential that $(E_{H^{+} / H_{2}}^{\circ} = 0)$ can release $H_{2}$ on reaction with dilute acid. So, $V^{+ 2}$ and ${Cr}^{+ 2}$ reduce $H^{+}$ to $H_{2}$ .

Q 11 :

The standard electrode potential of $M^{+} / M$ in aqueous solution does not depend on [2023]

Sublimation of a solid metal
Ionisation of a solid metal atom
Hydration of a gaseous metal ion
Ionisation of a gaseous metal atom

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(2)

The standard electrode potential of $M^{+} / M$ in aqueous solution depends on:

• Ionisation of a gaseous metal atom

• Hydration of a gaseous metal ion

• Sublimation of a solid metal

Q 12 :

The reaction

$\frac{1}{2} H_{2} (g) + AgCl (s) ⇌ H^{+} (aq) + {Cl}^{-} (aq) + Ag (s)$

occurs in which of the given galvanic cells? [2023]

$Pt | H_{2} (g) | HCl ({sol}^{n}) | AgCl (s) | Ag$
$Ag | AgCl (s) | KCl ({sol}^{n}) | {AgNO}_{3} | Ag$
$Pt | H_{2} (g) | HCl ({sol}^{n}) | {AgNO}_{3} ({sol}^{n}) | Ag$
$Pt | H_{2} (g) | KCl ({sol}^{n}) | AgCl (s) | Ag$

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(1)

Q 13 :

The standard reduction potentials at 298 K for the following half cells are given below:

${NO}_{3}^{-} + 4 H^{+} + 3 e^{-} \to NO(g) + 2 H_{2} O$ $E^{θ} = 0.97 V$

$V^{2 +} (a q) + 2 e^{-} \to V$ $E^{θ} = - 1.19 V$

${Fe}^{3 +} (a q) + 3 e^{-} \to Fe$ $E^{θ} = - 0.04 V$

${Ag}^{+} (a q) + e^{-} \to Ag(s)$ $E^{θ} = 0.80 V$

${Au}^{3 +} (a q) + 3 e^{-} \to Au(s)$ $E^{θ} = 1.40 V$

The number of metal(s) which will be oxidized by ${NO}_{3}^{-}$ in aqueous solution is _____________ . [2023]

(3)

${NO}_{3}^{-}$ can oxidise V, Fe and Ag.

Q 14 :

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

$Given: K_{s p} {Cu(OH)}_{2} = 1 \times 10^{- 20}$

$Take \frac{2.303 R T}{F} = 0.059 V$

The reduction potential at pH = 14 for the above couple is $(-) x \times 10^{- 2}$ V. The value of $x$ is __________ . [2023]

(25)

$pH = 14 \Rightarrow pOH = 0$

$[{OH}^{-}] = 1$

$K_{s p} {Cu(OH)}_{2} = [{Cu}^{2 +}] {[{OH}^{-}]}^{2} = 1 \times 10^{- 20}$

$[{Cu}^{2 +}] = 10^{- 20}$

$E_{{Cu}^{2 +} | Cu} = E_{{Cu}^{2 +} | Cu}^{0} - \frac{0.059}{2} \log \frac{1}{[{Cu}^{2 +}]}$

$= 0.34 - \frac{0.059}{2} \log 10^{20}$

$= - 0.25$

$= - 25 \times 10^{- 2} V$

Q 15 :

Consider the following electrochemical cell at 298 K:

$Pt | {HSnO}_{2}^{-} (a q) | Sn {(OH)}_{6}^{2 -} (a q) | {OH}^{-} (a q) | {Bi}_{2} O_{3} (s) | Bi (s)$

If the reaction quotient at a given time is $10^{6}$ , then the cell EMF $(E_{cell})$ is __________ $\times 10^{- 1} V$ (Nearest integer).

Given the standard half-cell reduction potentials as:

$E_{{Bi}_{2} O_{3} / Bi, {OH}^{-}}^{\circ} = - 0.44 V$ and $E_{{Sn(OH)}_{6}^{2 -} / {HSnO}_{2}^{-}, {OH}^{-}}^{\circ} = - 0.90 V$ [2026]

(4)

$E_{cell}^{\circ} = - 0.44 - (- 0.90)$

$= + 0.46 V$

$Applying Nernst equation:$

$E_{cell} = E_{cell}^{\circ} - \frac{0.06}{n} \log Q$

$E_{cell} = 0.46 - \frac{0.06}{6} \log 10^{6}$

$E_{cell} = 4 \times 10^{- 1}$

$x = 4$

Q 16 :

Consider the following reduction processes:

${Al}^{3 +} + 3 e^{-} ⟶ Al (s), E ° = - 1.66 V$

${Fe}^{3 +} + e^{-} ⟶ {Fe}^{2 +}, E ° = + 0.77 V$

${Co}^{3 +} + e^{-} ⟶ {Co}^{2 +}, E ° = + 1.81 V$

${Cr}^{3 +} + 3 e^{-} ⟶ Cr (s), E ° = - 0.74 V$

The tendency to act as reducing agent decreases in the order: [2026]

$Al > {Fe}^{2 +} > Cr > {Co}^{2 +}$
$Al > Cr > {Co}^{2 +} > {Fe}^{2 +}$
$Cr > {Fe}^{2 +} > Al > {Co}^{2 +}$
$Al > Cr > {Fe}^{2 +} > {Co}^{2 +}$

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(4)

$Reducing power \propto \frac{1}{Reduction potential}$

Q 17 :

Electrolysis of aqueous $C u S O_{4} (0.1 M)$ was carried out is two cells I and II. In I, the electrodes are of Cu and is II they were of Pt. As the electrolysis proceeds pH of the electrolyte solution will

decrease is II and remain the same in I
remain the same in both I and II
increase in both I and II
increase in I and decrease is II

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(1)

Q 18 :

Saturated solution of $K N O_{3}$ with agar-agar is used to make 'salt bridge' because:

size of $K^{+}$ is greater than that of $N O_{3}^{-}$
velocity of $N O_{3}^{-}$ is greater than that of $K^{+}$
velocities of both $K^{+}$ and $N O_{3}^{-}$ are nearly the same
both velocities and size of $K^{+}$ and $N O_{3}^{-}$ ions are same

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(3)

Q 19 :

Given at 298 K:

$E_{{Fe}^{2 +} / Fe}^{Θ} = X Volt$

$E_{{Fe}^{3 +} / Fe}^{Θ} = Y Volt$

The $E_{{Fe}^{3 +} / {Fe}^{2 +}}^{Θ}$ in Volt at 298 K is given by: [2026]

$2 X - 3 Y$
$3 Y - 2 X$
$3 Y + 2 X$
$Y + X$

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(2)

${Fe}^{2 +} + 2 e^{-} \to Fe, E_{{Fe}^{2 +} / Fe}^{o} = X,$

$Δ G_{{Fe}^{2 +} / Fe}^{o} = - n F E_{{Fe}^{2 +} / Fe}^{o} = - 2 F X$

Reverse this reaction

$Fe \to {Fe}^{2 +} + 2 e^{-}; E_{Fe / {Fe}^{2 +}}^{o} = - X,$

$Δ G_{Fe / {Fe}^{2 +}}^{o} = - n F E_{Fe / {Fe}^{2 +}}^{o} = - n F (- X) = 2 F X$

${Fe}^{3 +} + e^{-} \to Fe, E_{{Fe}^{3 +} / Fe}^{o} = Y$

$Δ G_{{Fe}^{3 +} / Fe}^{o} = - n F E_{{Fe}^{3 +} / Fe}^{o} = - 3 F Y$

Add above two reactions:

${Fe}^{3 +} + e^{-} \to {Fe}^{2 +}$

$Δ G_{{Fe}^{3 +} / {Fe}^{2 +}}^{o} = Δ G_{{Fe}^{3 +} / Fe}^{o} + Δ G_{Fe / {Fe}^{2 +}}^{o} = - 3 F Y + 2 F X$

$- n F E_{{Fe}^{3 +} / {Fe}^{2 +}}^{o} = - 3 F Y + 2 F X$

$- 1 F E_{{Fe}^{3 +} / {Fe}^{2 +}}^{o} = - 3 F Y + 2 F X$

$E_{{Fe}^{3 +} / {Fe}^{2 +}}^{o} = 3 Y - 2 X$

Topic Question Set

Q 1 :

One of the commonly used electrodes is calomel electrode. Under which of the following categories calomel electrode come? [2024]

Q 2 :

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

Q 3 :

Reduction potential of ions are given below:

${ClO}_{4}^{-}$ ${IO}_{4}^{-}$ ${BrO}_{4}^{-}$

$E^{°} = 1.19 V$ $E^{°} = 1.65 V$ $E^{°} = 1.74 V$

The correct order of their oxidising power is: [2024]

Q 6 :

${FeO}_{4}^{2 -} \overset{+ 2.0 V}{\to} {Fe}^{3 +} \overset{0.8 V}{\to} {Fe}^{2 +} \overset{- 0.5 V}{\to} {Fe}^{0}$

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

The value of $E_{{FeO}_{4}^{2 -} / {Fe}^{2 +}}^{⊝}$ is [2025]

Q 8 :

Based on the data given below:

$E_{{Cr}_{2} O_{7}^{2 -} / {Cr}^{3 +}}^{\circ} = 1.33 V E_{{Cl}_{2} / {Cl}^{-}}^{\circ} = 1.36 V$

$E_{{MnO}_{4}^{-} / {Mn}^{2 +}}^{\circ} = 1.51 V E_{{Cr}^{3 +} / Cr}^{\circ} = - 0.74 V$

The strongest reducing agent is: [2025]

Q 9 :

The standard reduction potential values of some of the $p$ -block ions are given below. Predict the one with the strongest oxidising capacity. [2025]

Q 10 :

The standard electrode potential $(M^{3 +} / M^{2 +})$ for V, Cr, Mn and Co are - 0.26 V, - 0.41 V, + 1.57 V and + 1.97 V, respectively. The metal ions which can liberate $H_{2}$ from a dilute acid are [2023]

Q 11 :

The standard electrode potential of $M^{+} / M$ in aqueous solution does not depend on [2023]

Q 12 :

The reaction

$\frac{1}{2} H_{2} (g) + AgCl (s) ⇌ H^{+} (aq) + {Cl}^{-} (aq) + Ag (s)$

occurs in which of the given galvanic cells? [2023]

Q 17 :

Electrolysis of aqueous $C u S O_{4} (0.1 M)$ was carried out is two cells I and II. In I, the electrodes are of Cu and is II they were of Pt. As the electrolysis proceeds pH of the electrolyte solution will

(1)

Q 18 :

Saturated solution of $K N O_{3}$ with agar-agar is used to make 'salt bridge' because:

(3)

Q 19 :

Given at 298 K:

$E_{{Fe}^{2 +} / Fe}^{Θ} = X Volt$

$E_{{Fe}^{3 +} / Fe}^{Θ} = Y Volt$

The $E_{{Fe}^{3 +} / {Fe}^{2 +}}^{Θ}$ in Volt at 298 K is given by: [2026]

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	List I		List II
	(Cell)		(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 $Zn \to {Zn}^{2 +} + 2 e^{-}$

Topic Question Set

Q 1 : One of the commonly used electrodes is calomel electrode. Under which of the following categories calomel electrode come? [2024]

Q 2 : How can an electrochemical cell be converted into an electrolytic cell?

Q 3 : Reduction potential of ions are given below: ClO4- IO4- BrO4- E°=1.19V E°=1.65V E°=1.74V The correct order of their oxidising power is: [2024]

Q 6 : FeO42-→+2.0 VFe3+→0.8 VFe2+→-0.5 VFe0 In the above diagram, the standard electrode potentials are given in volts (over the arrow). The value of EFeO42-/Fe2+⊝ is [2025]

Q 7 : For the given cell Fe2+(aq)+Ag+(aq)→Fe3+(aq)+Ag(s) The standard cell potential of the above reaction is: Given: Ag++e-→Ag Eθ=x V Fe2++2e-→Fe Eθ=y V Fe3++3e-→Fe Eθ=z V [2025]

Q 8 : Based on the data given below: ECr2O72-/Cr3+∘=1.33 V ECl2/Cl-∘=1.36 V EMnO4-/Mn2+∘=1.51 V ECr3+/Cr∘=-0.74 V The strongest reducing agent is: [2025]

Q 9 : The standard reduction potential values of some of the p-block ions are given below. Predict the one with the strongest oxidising capacity. [2025]

Q 10 : The standard electrode potential (M3+/M2+) for V, Cr, Mn and Co are - 0.26 V, - 0.41 V, + 1.57 V and + 1.97 V, respectively. The metal ions which can liberate H2 from a dilute acid are [2023]

Q 11 : The standard electrode potential of M+/M in aqueous solution does not depend on [2023]

Q 12 : The reaction 12H2(g)+AgCl(s)⇌H+(aq)+Cl-(aq)+Ag(s) occurs in which of the given galvanic cells? [2023]

Q 14 : At 298 K, the standard reduction potential for the Cu2+/Cu electrode is 0.34 V. Given: KspCu(OH)2=1×10-20 Take 2.303RTF=0.059 V The reduction potential at pH = 14 for the above couple is (-)x×10-2V. The value of x is __________ . [2023]

Q 16 : Consider the following reduction processes: Al3++3e-⟶Al(s), E°=-1.66 V Fe3++e-⟶Fe2+, E°=+0.77 V Co3++e-⟶Co2+, E°=+1.81 V Cr3++3e-⟶Cr(s), E°=-0.74 V The tendency to act as reducing agent decreases in the order: [2026]

Q 17 : Electrolysis of aqueous CuSO4(0.1 M) was carried out is two cells I and II. In I, the electrodes are of Cu and is II they were of Pt. As the electrolysis proceeds pH of the electrolyte solution will

(1)

Q 18 : Saturated solution of KNO3 with agar-agar is used to make 'salt bridge' because:

(3)

Q 19 : Given at 298 K: EFe2+/FeΘ=X Volt EFe3+/FeΘ=Y Volt The EFe3+/Fe2+Θ in Volt at 298 K is given by: [2026]

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Q 1 :

One of the commonly used electrodes is calomel electrode. Under which of the following categories calomel electrode come? [2024]

Q 2 :

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

Q 3 :

Reduction potential of ions are given below:

${ClO}_{4}^{-}$ ${IO}_{4}^{-}$ ${BrO}_{4}^{-}$

$E^{°} = 1.19 V$ $E^{°} = 1.65 V$ $E^{°} = 1.74 V$

The correct order of their oxidising power is: [2024]

Q 6 :

${FeO}_{4}^{2 -} \overset{+ 2.0 V}{\to} {Fe}^{3 +} \overset{0.8 V}{\to} {Fe}^{2 +} \overset{- 0.5 V}{\to} {Fe}^{0}$

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

The value of $E_{{FeO}_{4}^{2 -} / {Fe}^{2 +}}^{⊝}$ is [2025]

Q 8 :

Based on the data given below:

$E_{{Cr}_{2} O_{7}^{2 -} / {Cr}^{3 +}}^{\circ} = 1.33 V E_{{Cl}_{2} / {Cl}^{-}}^{\circ} = 1.36 V$

$E_{{MnO}_{4}^{-} / {Mn}^{2 +}}^{\circ} = 1.51 V E_{{Cr}^{3 +} / Cr}^{\circ} = - 0.74 V$

The strongest reducing agent is: [2025]

Q 9 :

The standard reduction potential values of some of the $p$ -block ions are given below. Predict the one with the strongest oxidising capacity. [2025]

Q 10 :

The standard electrode potential $(M^{3 +} / M^{2 +})$ for V, Cr, Mn and Co are - 0.26 V, - 0.41 V, + 1.57 V and + 1.97 V, respectively. The metal ions which can liberate $H_{2}$ from a dilute acid are [2023]

Q 11 :

The standard electrode potential of $M^{+} / M$ in aqueous solution does not depend on [2023]

Q 12 :

The reaction

$\frac{1}{2} H_{2} (g) + AgCl (s) ⇌ H^{+} (aq) + {Cl}^{-} (aq) + Ag (s)$

occurs in which of the given galvanic cells? [2023]

Q 17 :

Electrolysis of aqueous $C u S O_{4} (0.1 M)$ was carried out is two cells I and II. In I, the electrodes are of Cu and is II they were of Pt. As the electrolysis proceeds pH of the electrolyte solution will

Q 18 :

Saturated solution of $K N O_{3}$ with agar-agar is used to make 'salt bridge' because:

Q 19 :

Given at 298 K:

$E_{{Fe}^{2 +} / Fe}^{Θ} = X Volt$

$E_{{Fe}^{3 +} / Fe}^{Θ} = Y Volt$

The $E_{{Fe}^{3 +} / {Fe}^{2 +}}^{Θ}$ in Volt at 298 K is given by: [2026]