JEE Main 2021 · ChemistryNumerical answerNumerical valueMediumCalculation

JEE Main 26 February 2021, Shift 2, Chemistry Q57

Question 57 of 90 in this shift, Chemistry question 27 of 30, Section B.

Emf of the following cell at 298 K in V is

x \times 10^{-2}

\mathrm{Zn|Zn^{2+}}

(0.1 M)

\|

\mathrm{Ag^+}

(0.01 M)

|

Ag The value of

x

is __________. (Rounded off to the nearest integer) [Given :

\mathrm{E^{\theta}_{Zn^{2+}/Zn}} = -0.76

V ;

\mathrm{E^{\theta}_{Ag^+/Ag}} = +0.80

V ;

\frac{2.303RT}{F} = 0.059

]

Official answer

147

NTA final key.

Chapter: Electrochemistry
Topic: Nernst Equation
Idea tested: Full Cell Nernst Equation

Same idea in other shifts

Asked 12× in all

4 Apr 2026, Shift 2 · Q73An electrochemical cell, consist of the following two redox couples, $\mathrm{M^{x+}(aq)/M(s)}$ $[E^\ominus_{red}=+0.15\ \mathrm{V}]$ and…HardNumerical value
5 Apr 2026, Shift 2 · Q57One half cell in a voltaic cell is constructed by dipping silver rod in $\mathrm{AgNO_3}$ solution of unknown concentration, other half…MediumSingle correct
7 Apr 2025, Shift 1 · Q711 Faraday electricity was passed through $\mathrm{Cu^{2+}}$ (1.5 M, 1 L) /Cu and 0.1 Faraday was passed through $\mathrm{Ag^+}$ (0.2 M, 1…HardNumerical valueHas a figure
8 Apr 2024, Shift 2 · Q63The emf of cell $\mathrm{Tl\,|\,Tl^+(0.001\,M)\,||\,Cu^{2+}(0.01\,M)\,|\,Cu}$ is 0.83 V at 298 K. It could be increased by :MediumSingle correct
25 Jul 2022, Shift 1 · Q84The cell potential for $\mathrm{Zn|Zn^{2+}(aq)\|Sn^{x+}|\,Sn}$ is $0.801$ V at 298 K. The reaction quotient for the above reaction is…MediumNumerical value
29 Jul 2022, Shift 2 · Q84For a cell, $\mathrm{Cu(s) \mid Cu^{2+}(0.001M) \mid\mid Ag^{+}(0.01M) \mid Ag(s)}$ the cell potential is found to be 0.43 V at 298 K. The…MediumNumerical value
24 Jun 2022, Shift 1 · Q84The cell potential for the following cell $\mathrm{Pt\,|H_2(g)|H^+(aq)\|\ Cu^{2+}(0.01\ M)|Cu(s)}$ is 0.576 V at 298 K. The pH of the…MediumNumerical value
26 Aug 2021, Shift 2 · Q56For the galvanic cell, $\mathrm{Zn(s) + Cu^{2+}}$ (0.02 M) $\rightarrow \mathrm{Zn^{2+}}$ (0.04 M) $+ \mathrm{Cu(s)}$ , $\mathrm{E_{cell}}$ …MediumNumerical value

Question text from the official JEE Main paper published by NTA; answer from the final answer key. Chapter, topic and idea tags, difficulty and skill are Lumi’s. Lumi analyses 108 of the 174 JEE Main shifts held from 2017 to 2026.