1
JEE Main 2025 (Online) 3rd April Evening Shift
MCQ (Single Correct Answer)
+4
-1
Change Language

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 reduction potential for $\mathrm{O}_2\left(\mathrm{E}_{\mathrm{O}_2 / \mathrm{H}_2 \mathrm{O}}^{\circ}\right)$ is 1.229 V .

Choose the correct statement :

A
Reactants are fed at one go to each electrode.
B
Oxygen is formed at the anode.
C
The standard half cell reduction potential for the reduction of $\mathrm{CO}_2\left(\mathrm{E}_{\mathrm{CO}_2 / \mathrm{CH}_3 \mathrm{OH}}^{\circ}\right)$ is 19 mV
D
Reduction of methanol takes place at the cathode.
2
JEE Main 2025 (Online) 3rd April Morning Shift
MCQ (Single Correct Answer)
+4
-1
Change Language
Correct order of limiting molar conductivity for cations in water at 298 K is :
A

$\mathrm{H}^{+}>\mathrm{Na}^{+}>\mathrm{K}^{+}>\mathrm{Ca}^{2+}>\mathrm{Mg}^{2+}$

B

$\mathrm{H}^{+}>\mathrm{Ca}^{2+}>\mathrm{Mg}^{2+}>\mathrm{K}^{+}>\mathrm{Na}^{+}$

C

$\mathrm{Mg}^{2+}>\mathrm{H}^{+}>\mathrm{Ca}^{2+}>\mathrm{K}^{+}>\mathrm{Na}^{+}$

D

$\mathrm{H}^{+}>\mathrm{Na}^{+}>\mathrm{Ca}^{2+}>\mathrm{Mg}^{2+}>\mathrm{K}^{+}$

3
JEE Main 2025 (Online) 29th January Evening Shift
MCQ (Single Correct Answer)
+4
-1
Change Language

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 (III) Anode - Zn; Cathode - Carbon
(D) Apollo space ship (IV) Anode - Pb; Cathode - Pb | PbO2

Choose the correct answer from the options given below :

A

(A)-(III), (B)-(I), (C)-(IV), (D)-(II)

B

(A)-(II), (B)-(III), (C)-(IV), (D)-(I)

C

(A)-(IV), (B)-(III), (C)-(II), (D)-(I)

D

(A)-(III), (B)-(II), (C)-(IV), (D)-(I)

4
JEE Main 2025 (Online) 29th January Evening Shift
MCQ (Single Correct Answer)
+4
-1
Change Language

$\mathrm{O}_2$ 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 $\mathrm{H}_2 \mathrm{SO}_4$ using platinum electrodes.

(D) a high concentration solution of $\mathrm{H}_2 \mathrm{SO}_4$ using platinum electrodes.

Choose the correct answer from the options given below :

A
(B) and (C) only
B
(B) and (D) only
C
(A) and (D) only
D
$(A)$ and $(C)$ only
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