The standard reduction potentials at 298 K for the following half cells are given below : $\mathrm{Cr_2O_7^{2-}} + 14\mathrm{H^+} + 6e^- \rightarrow 2\mathrm{Cr^{3+}} + 7\mathrm{H_2O}$, $E^\circ = 1.33$ V $\mathrm{Fe^{3+}(aq)} + 3e^- \rightarrow \mathrm{Fe}$ $E^\circ = -0.04$ V $\mathrm{Ni^{2+}(aq)} + 2e^- \rightarrow \mathrm{Ni}$ $E^\circ = -0.25$ V $\mathrm{Ag^+(aq)} + e^- \rightarrow \mathrm{Ag}$ $E^\circ = 0.80$ V $\mathrm{Au^{3+}(aq)} + 3e^- \rightarrow \mathrm{Au}$ $E^\circ = 1.40$ V Consider the given electrochemical reactions, The number of metal(s) which will be oxidized be $\mathrm{Cr_2O_7^{2-}}$, in aqueous solution is ________.

JEE Main 2024 · ChemistryNumerical answerNumerical valueMediumApplication

JEE Main 9 April 2024, Shift 1, Chemistry Q85

Question 85 of 90 in this shift, Chemistry question 25 of 30, Section B.

The standard reduction potentials at 298 K for the following half cells are given below :

\mathrm{Cr_2O_7^{2-}} + 14\mathrm{H^+} + 6e^- \rightarrow 2\mathrm{Cr^{3+}} + 7\mathrm{H_2O}

E^\circ = 1.33

\mathrm{Fe^{3+}(aq)} + 3e^- \rightarrow \mathrm{Fe}

E^\circ = -0.04

\mathrm{Ni^{2+}(aq)} + 2e^- \rightarrow \mathrm{Ni}

E^\circ = -0.25

\mathrm{Ag^+(aq)} + e^- \rightarrow \mathrm{Ag}

E^\circ = 0.80

\mathrm{Au^{3+}(aq)} + 3e^- \rightarrow \mathrm{Au}

E^\circ = 1.40

V Consider the given electrochemical reactions, The number of metal(s) which will be oxidized be

\mathrm{Cr_2O_7^{2-}}

, in aqueous solution is ________.

Official answer

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.