For the reaction $2{\mathrm{Fe}}^{3+}(\mathrm{aq})+2{I}^{-}(\mathrm{aq})\rightarrow 2{\mathrm{Fe}}^{2+}(\mathrm{aq})+{I}_{2}(s)$ the magnitude of the standard molar free energy change, ${\Delta }_{r}{G}_{m}^{\circ }=-$______$\mathrm{kJ}$ (Round off to the Nearest Integer). ![JEE Main 2021 Chemistry, Electrochemistry — question figure](https://prepforbharat.s3.ap-south-1.amazonaws.com/exam/615f0e999476412f48314daf/Chemistry/images/Electrochemistry/648b5a69417cc3fb48d6700b/question_1__q_648b5a69417cc3fb48d6700b__cdn-question-pool.getmarks.app__25322c0c-f583-44c3-898c-7021b2474158-image__724400dce9_final_ppt_sync.png)

Standard electrode potential is a measurement of the potential for equilibrium. There is a potential difference between the electrode and the electrolyte called the potential of the electrode. When unity is the concentrations of all the species involved in a semi-cell, the electrode potential is known as the standard electrode potential. ![JEE Main 2021 Chemistry, Electrochemistry — solution figure](https://prepforbharat.s3.ap-south-1.amazonaws.com/exam/615f0e999476412f48314daf/Chemistry/images/Electrochemistry/648b5a69417cc3fb48d6700b/solution_1__q_648b5a69417cc3fb48d6700b__cdn-question-pool.getmarks.app__0112f096-adc8-41ca-afdb-607a7d478352-image__9084f8bab7_final_ppt_sync.png) ${E}_{1}^{0}+2{E}_{2}^{0}=3{E}_{3}^{0}$ ${E}_{1}^{0}=3{E}_{3}^{0}-2{E}_{2}^{0}$ $=3(-0.036)-2(-0.44)$ $=+0.772V$ ${E}_{\text{cell }}^{0}={E}_{{\mathrm{Fe}}^{3+}/{\mathrm{Fe}}^{2+}}^{0}+{E}_{{I}^{-}/{I}_{2}}^{0}=0.233$ ${\Delta }_{r}{G}^{0}=-2\times 96.5\times 0.233=-45\mathrm{kJ}$

JEE Main 2021 — Chemistry Physical Chemistry

2021integermedium

For the reaction

$2{\mathrm{Fe}}^{3+}(\mathrm{aq})+2{I}^{-}(\mathrm{aq})\rightarrow 2{\mathrm{Fe}}^{2+}(\mathrm{aq})+{I}_{2}(s)$

the magnitude of the standard molar free energy change, ${\Delta }_{r}{G}_{m}^{\circ }=-$ ______ $\mathrm{kJ}$ (Round off to the Nearest Integer).

JEE Main 2021 Chemistry, Electrochemistry — question figure

Official previous-year question

Held on 18 Mar 2021 · Verified 6 Jul 2026.

Did you get this right?

Solution

Standard electrode potential is a measurement of the potential for equilibrium. There is a potential difference between the electrode and the electrolyte called the potential of the electrode. When unity is the concentrations of all the species involved in a semi-cell, the electrode potential is known as the standard electrode potential.

JEE Main 2021 Chemistry, Electrochemistry — solution figure

${E}_{1}^{0}+2{E}_{2}^{0}=3{E}_{3}^{0}$

${E}_{1}^{0}=3{E}_{3}^{0}-2{E}_{2}^{0}$

$=3(-0.036)-2(-0.44)$

$=+0.772V$

${E}_{\text{cell }}^{0}={E}_{{\mathrm{Fe}}^{3+}/{\mathrm{Fe}}^{2+}}^{0}+{E}_{{I}^{-}/{I}_{2}}^{0}=0.233$

${\Delta }_{r}{G}^{0}=-2\times 96.5\times 0.233=-45\mathrm{kJ}$

Your note

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JEE Main 2021 — Chemistry Physical Chemistry

2021integermedium

For the reaction

$2{\mathrm{Fe}}^{3+}(\mathrm{aq})+2{I}^{-}(\mathrm{aq})\rightarrow 2{\mathrm{Fe}}^{2+}(\mathrm{aq})+{I}_{2}(s)$

the magnitude of the standard molar free energy change, ${\Delta }_{r}{G}_{m}^{\circ }=-$ ______ $\mathrm{kJ}$ (Round off to the Nearest Integer).

JEE Main 2021 Chemistry, Electrochemistry — question figure

Official previous-year question

Held on 18 Mar 2021 · Verified 6 Jul 2026.

Did you get this right?

Solution

JEE Main 2021 Chemistry, Electrochemistry — solution figure

${E}_{1}^{0}+2{E}_{2}^{0}=3{E}_{3}^{0}$

${E}_{1}^{0}=3{E}_{3}^{0}-2{E}_{2}^{0}$

$=3(-0.036)-2(-0.44)$

$=+0.772V$

${E}_{\text{cell }}^{0}={E}_{{\mathrm{Fe}}^{3+}/{\mathrm{Fe}}^{2+}}^{0}+{E}_{{I}^{-}/{I}_{2}}^{0}=0.233$

${\Delta }_{r}{G}^{0}=-2\times 96.5\times 0.233=-45\mathrm{kJ}$

Your note

JEE Main Physical Chemistry in other years

Keep practicing Physical Chemistry

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

Browse all Chemistry topics

JEE Main 2021 — Chemistry Physical Chemistry

Did you get this right?

Solution

Your note

JEE Main Physical Chemistry in other years

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Organic Chemistry

Inorganic Chemistry

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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