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Friday, 9 October

JEE Main 2026 · ChemistryNumerical answerNumerical valueHardMulti-step

JEE Main 4 April 2026, Shift 2, Chemistry Q73

Question 73 of 75 in this shift, Chemistry question 23 of 25, Section B.

An electrochemical cell, consist of the following two redox couples, Mx+(aq)/M(s)\mathrm{M^{x+}(aq)/M(s)} [Ered⊖=+0.15 V][E^\ominus_{red}=+0.15\ \mathrm{V}] and Fe3+(aq)/Fe(s)\mathrm{Fe^{3+}(aq)/Fe(s)} [Ered⊖=−0.036 V][E^\ominus_{red}=-0.036\ \mathrm{V}]. The cell EMF (EcellE_{cell}) is recorded to be 0.2057 V. If the reaction quotient of the electrochemical reaction is found to be 10−210^{-2}, then the value of xx is ________.(Nearest integer) [Given : M is a p-block metal and 2.303RTF=0.059 V\frac{2.303RT}{F}=0.059\ \mathrm{V}]

Official answer

2

NTA final key.

Chapter
Electrochemistry
Topic
Nernst Equation
Idea tested
Full Cell Nernst Equation

Same idea in other shifts

Asked 6× in all
  1. 5 Apr 2026, Shift 2 · Q57One half cell in a voltaic cell is constructed by dipping silver rod in AgNO3\mathrm{AgNO_3} solution of unknown concentration, other half…MediumSingle correct
  2. 7 Apr 2025, Shift 1 · Q711 Faraday electricity was passed through Cu2+\mathrm{Cu^{2+}} (1.5 M, 1 L) /Cu and 0.1 Faraday was passed through Ag+\mathrm{Ag^+} (0.2 M, 1…HardNumerical valueHas a figure
  3. 25 Jul 2022, Shift 1 · Q84The cell potential for Zn∣Zn2+(aq)∥Snx+∣ Sn\mathrm{Zn|Zn^{2+}(aq)\|Sn^{x+}|\,Sn} is 0.8010.801 V at 298 K. The reaction quotient for the above reaction is…MediumNumerical value
  4. 24 Jun 2022, Shift 1 · Q84The cell potential for the following cell Pt ∣H2(g)∣H+(aq)∥ Cu2+(0.01 M)∣Cu(s)\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
  5. 25 Jul 2021, Shift 1 · Q58Consider the cell at 25∘^\circC Zn∣Zn2+(aq),(1 M) ∣∣ Fe3+(aq),Fe2+(aq)∣Pt(s)\mathrm{Zn|Zn^{2+}(aq),(1\ M)\,||\,Fe^{3+}(aq),Fe^{2+}(aq)|Pt(s)} The fraction of total iron present as…HardNumerical 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 42 of the 174 JEE Main shifts held from 2017 to 2026.