JEE Main 2022 · ChemistryMultiple choiceSingle correctEasyConceptual

JEE Main 30 July 2022, Shift 2, Chemistry Q39

Question 39 of 90 in this shift, Chemistry question 9 of 30, Section A.

The

\mathrm{E^o}

(volt) values are :

\mathrm{Al^{3+}/Al}

-1.66

\mathrm{Sc^{3+}/Sc}

-2.08

\mathrm{Fe^{3+}/Fe^{2+}}

+0.77

\mathrm{Hg_2^{2+}/Hg}

+0.79

. Arrangement of cations,

\mathrm{Al^{3+}}

\mathrm{Sc^{3+}}

\mathrm{Fe^{3+}}

and

\mathrm{Hg_2^{2+}}

in decreasing order of oxidizing strength is

(1) $\mathrm{Al^{3+}} > \mathrm{Sc^{3+}} > \mathrm{Fe^{3+}} > \mathrm{Hg_2^{2+}}$
(2) $\mathrm{Hg_2^{2+}} > \mathrm{Fe^{3+}} > \mathrm{Sc^{3+}} > \mathrm{Al^{3+}}$
(3) $\mathrm{Hg_2^{2+}} > \mathrm{Fe^{3+}} > \mathrm{Al^{3+}} > \mathrm{Sc^{3+}}$ Official answer
(4) $\mathrm{Sc^{3+}} > \mathrm{Al^{3+}} > \mathrm{Fe^{3+}} > \mathrm{Hg_2^{2+}}$

Official answer

Option 3

NTA final key.

Chapter: Electrochemistry
Topic: Nernst Equation
Idea tested: Standard Cell Potential

Same idea in other shifts

Asked 13× in all

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.