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Saturday, 31 October

JEE Main 2021 · ChemistryNumerical answerNumerical valueMediumCalculation

JEE Main 24 February 2021, Shift 2, Chemistry Q56

Question 56 of 90 in this shift, Chemistry question 26 of 30, Section B.

The magnitude of the change in oxidising power of the MnO4−/Mn2+\mathrm{MnO_4^-/Mn^{2+}} couple is x×10−4x \times 10^{-4} V, if the H+\mathrm{H^+} concentration is decreased from 1 M to 10−410^{-4} M at 25∘25^\circC. (Assume concentration of MnO4−\mathrm{MnO_4^-} and Mn2+\mathrm{Mn^{2+}} to be same on change in H+\mathrm{H^+} concentration). The value of xx is __________. (Rounded off to the nearest integer) [Given : 2.303 RTF=0.059\frac{2.303\,\mathrm{RT}}{\mathrm{F}} = 0.059]

Official answer

3776

NTA final key.

Chapter
Electrochemistry
Topic
Nernst Equation
Idea tested
pH Dependence of Electrode Potential

Same idea in other shifts

Asked 6× in all
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  3. 30 Jun 2022, Shift 1 · Q65In which of the following half cells, electrochemical reaction is pH dependent ?EasySingle correct
  4. 25 Feb 2021, Shift 2 · Q56Copper reduces NO3−\mathrm{NO_3^-} into NO and NO2\mathrm{NO_2} depending upon the concentration of HNO3\mathrm{HNO_3} in solution. (Assuming…HardNumerical value
  5. 8 Jan 2020, Shift 1 · Q48What would be the electrode potential for the given half cell reaction at pH=5 ? ______.…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.