Chemistry · Electrochemistry

JEE Main 2026 — 4 April, Evening Shift — Question 64

An electrochemical cell. consist of the following two redox couples, Mx+(aq)/M(s)[Ered ⊖=+0.15 V]\mathrm{M}^{\mathrm{x}+}(\mathrm{aq}) / \mathrm{M}(\mathrm{s})\left[\mathrm{E}_{\text {red }}^{\ominus}=+0.15 \mathrm{~V}\right] and Fe3+(aq)/Fe(s)[Ered ⊖=−0.036 V]\mathrm{Fe}^{3+}(\mathrm{aq}) / \mathrm{Fe}(\mathrm{s})\left[\mathrm{E}_{\text {red }}^{\ominus}=-0.036 \mathrm{~V}\right] The cell EMF ( Ecell \mathrm{E}_{\text {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 x is ____\_\_\_\_ (Nearest integer)[0pt] [Given : M is a p-block metal and 2.303RTF=0.059 V]\left.\frac{2.303 \mathrm{RT}}{\mathrm{F}}=0.059 \mathrm{~V}\right]

Answer: 2

Numerical answer — enter this value.

Step-by-step solution

Ecell =Ecell o−0.0593xlog⁡10−2\mathrm{E}_{\text {cell }}=\mathrm{E}_{\text {cell }}^{\mathrm{o}}-\frac{0.059}{3 \mathrm{x}} \log 10^{-2} 0.2057=0.186−0.0593x(−2)0.2057=0.186-\frac{0.059}{3 \mathrm{x}}(-2) 3x=0.059×20.01973 \mathrm{x}=\frac{0.059 \times 2}{0.0197} x=1.99≃2\mathrm{x}=1.99 \simeq 2

Answer key and solution verified before publishing.

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Exam
JEE Main 2026
Subject
Chemistry
Chapter
Electrochemistry
Topic
Nernst Equation and Electrochemical Series
An electrochemical cell. consist of the following two redox couples… | JEE Main 2026 PYQ with Solution · DhiX AI