JEE Main · 2026 · 21 Jan 2026 · Shift 2 · Redox Reactions and Electrochemistry

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

(A)(see structure)
(B)(see structure)
✓ Correct
(C)(see structure)
(D)(see structure)

Answer: (B)

Solution

At a fixed temperature the standard cell potential

E_{cell}^{\circ}

is fixed entirely by the standard electrode potentials of the zinc and copper couples, quantities that depend only on temperature. It carries no dependence on how long the cell runs or on the changing half-cell concentrations, since those effects enter through the Nernst term and belong to

E_{cell}

, not to

E_{cell}^{\circ}

. A plot of

E_{cell}^{\circ}

against time is therefore a straight horizontal line of constant height.

JEE Main · 2026 · 21 Jan 2026 · Shift 2 · Single correct option

Practise more: all JEE Main PYQs on Redox Reactions and Electrochemistry →

More JEE Main questions on Redox Reactions and Electrochemistry

The pH and conductance of a weak acid (HX) was found to be 5 and $4 \times 1 0^{- 5} S$ , respectively. The conductance was measured under standard condition using a cell where the electrode plates having a surface area of $1 cm^{2}$ were at a distance of 15 cm a …
JEE Main 2026View solution →
Consider the following electrochemical cell at 298 K
$Pt HSnO_{2}^{-} (aq) Sn (OH)_{6}^{2 -} (aq) ∣ Bi_{2} O_{3} (s) ∣ Bi (s)$ .
If the reaction quotient at a giv …
JEE Main 2026View solution →
Aqueous HCl reacts with $MnO_{2} (s)$ to form $MnCl_{2} (aq)$ , $Cl_{2} (g)$ and $H_{2} O (l)$ . What is the weight (in g) of $Cl_{2}$ liberated when 8.7 g of $MnO_{2} (s)$ is reacted w …
JEE Main 2026View solution →
MX is a sparingly soluble salt that follows the given solubility equilibrium at 298 K
$MX (s) ⇌ M^{+} (aq) + X^{-} (aq)$ ; $K_{sp} = 1 0^{- 10}$
If the standard reduction potential for …
JEE Main 2026View solution →
Consider the following reduction processes:
$Al^{3 +} + 3 e^{-} \to Al (s), E^{\circ} = - 1.66 V$
$Fe^{3 +} + e^{-} \to Fe^{2 +}, E^{\circ} = + 0.77 V$ …
JEE Main 2026View solution →
Consider the following electrochemical cell:
$Pt ∣ O_{2} (g) (1 bar) ∣ HCl (aq) ∣∣ M^{2 +} (aq, 1.0 M) ∣ M (s)$
The pH above which, oxygen gas would start to evolve at anode is _____ (nearest inte …
JEE Main 2026View solution →