JEE Main 2021 — Chemistry Physical Chemistry

2021integermedium

$\mathrm{Emf}$ of the following cell at $298K$ in $V$ is $x\times {10}^{-2}$

$\mathrm{Zn}|{\mathrm{Zn}}^{2+}(0.1M)\|{\mathrm{Ag}}^{+}(0.01M)|\mathrm{Ag}$

The value of $x$ is ________________ (Rounded off to the nearest integer)

$[\mathrm{Given}:{E}_{{\mathrm{Zn}}^{2+}/\mathrm{Zn}}^{\theta }=-0.76V;{E}_{{\mathrm{Ag}}^{+}/\mathrm{Ag}}^{\theta }=+0.80V;\frac{2.303\mathrm{RT}}{F}=0.059]$

Official previous-year question

Held on 26 Feb 2021 · Verified 6 Jul 2026.

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Solution

JEE Main 2021 Chemistry, Electrochemistry — solution figure

${E}_{\mathrm{cell}}^{0}={E}_{{\mathrm{Ag}}^{+}/\mathrm{Ag}}^{0}-{E}_{{\mathrm{Zn}}^{2+}/\mathrm{Zn}}^{0}$

$=0.80-(-0.76)$

$=1.56V$

${E}_{\mathrm{cell}}=1.56-\frac{0.059}{2}\mathrm{log}\frac{[{\mathrm{Zn}}^{2+}]}{{[{\mathrm{Ag}}^{+}]}^{2}}$

$=1.56-\frac{0.059}{2}\mathrm{log}\frac{0.1}{{(0.01)}^{2}}$

$=1.56-\frac{0.059}{2}\times 3$

$=1.56-0.0885$

$=1.4715$

$=147.15\times {10}^{-2}$

Your note

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JEE Main 2021 — Chemistry Physical Chemistry

2021integermedium

$\mathrm{Emf}$ of the following cell at $298K$ in $V$ is $x\times {10}^{-2}$

$\mathrm{Zn}|{\mathrm{Zn}}^{2+}(0.1M)\|{\mathrm{Ag}}^{+}(0.01M)|\mathrm{Ag}$

The value of $x$ is ________________ (Rounded off to the nearest integer)

$[\mathrm{Given}:{E}_{{\mathrm{Zn}}^{2+}/\mathrm{Zn}}^{\theta }=-0.76V;{E}_{{\mathrm{Ag}}^{+}/\mathrm{Ag}}^{\theta }=+0.80V;\frac{2.303\mathrm{RT}}{F}=0.059]$

Official previous-year question

Held on 26 Feb 2021 · Verified 6 Jul 2026.

Did you get this right?

Solution

JEE Main 2021 Chemistry, Electrochemistry — solution figure

${E}_{\mathrm{cell}}^{0}={E}_{{\mathrm{Ag}}^{+}/\mathrm{Ag}}^{0}-{E}_{{\mathrm{Zn}}^{2+}/\mathrm{Zn}}^{0}$

$=0.80-(-0.76)$

$=1.56V$

${E}_{\mathrm{cell}}=1.56-\frac{0.059}{2}\mathrm{log}\frac{[{\mathrm{Zn}}^{2+}]}{{[{\mathrm{Ag}}^{+}]}^{2}}$

$=1.56-\frac{0.059}{2}\mathrm{log}\frac{0.1}{{(0.01)}^{2}}$

$=1.56-\frac{0.059}{2}\times 3$

$=1.56-0.0885$

$=1.4715$

$=147.15\times {10}^{-2}$

Your note

JEE Main Physical Chemistry in other years

Keep practicing Physical Chemistry

Work through every JEE Main Physical Chemistry PYQ, year by year.

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JEE Main 2021 — Chemistry Physical Chemistry

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Solution

Your note

JEE Main Physical Chemistry in other years

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JEE Main 2021 — Chemistry Physical Chemistry

Did you get this right?

Solution

Your note

JEE Main Physical Chemistry in other years

More JEE Main Physical Chemistry questions

Other Chemistry topics for JEE Main

Organic Chemistry

Inorganic Chemistry

Keep practicing Physical Chemistry