JEE Main 2023 — Chemistry Physical Chemistry

2023integermedium

When ${\mathrm{Fe}}_{0.93}O$ is heated in presence of oxygen, it converts to ${\mathrm{Fe}}_{2}{O}_{3}$ . The number of correct statement/s from the following is ______ .

A. The equivalent weight of ${\mathrm{Fe}}_{0.93}O$ is $\frac{\mathrm{Molecular}\mathrm{weight}}{0.79}$

B. The number of moles of ${\mathrm{Fe}}^{2+}$ and ${\mathrm{Fe}}^{3+}$ in $1$ mole of ${\mathrm{Fe}}_{0.93}O$ is $0.79$ and $0.14$ respectively.

C. ${\mathrm{Fe}}_{0.93}O$ is metal deficient with lattice comprising of cubic closed packed arrangement of ${O}^{2-}$ ions.

D. The $%$ composition of ${\mathrm{Fe}}^{2+}$ and ${\mathrm{Fe}}^{3+}$ in ${\mathrm{Fe}}_{0.93}O$ is $85%$ and $15%$ respectively.

Official previous-year question

Held on 24 Jan 2023 · Verified 6 Jul 2026.

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Solution

$A:{\mathrm{Fe}}_{0.93}O\rightarrow {\mathrm{Fe}}_{2}{O}_{3}$

The valence factor of ${\mathrm{Fe}}_{0.93}O$ , $\mathrm{nf}=(3-\frac{200}{93})\times 0.93$

$\mathrm{nf}=0.79$

Hence, the equivalent weight $=\frac{\mathrm{Molecular}\mathrm{weight}}{0.79}$

$B:2x+(0.93-x)\times 3=2$

$x=0.79$

${\mathrm{Fe}}^{2+}=0.79,{\mathrm{Fe}}^{3+}=0.14$

$C:$ In ${\mathrm{Fe}}_{0.93}O$ , ${O}^{2-}$ ions forms the lattice and iron ions occupies the voids in the lattice. As sufficient number of irons are not available, this metal oxide is said to be metal difficient.

$D:%{\mathrm{Fe}}^{2+}=\frac{0.79}{0.93}\times 100=85%;{\mathrm{Fe}}^{3+}=15%$

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Solution

$A:{\mathrm{Fe}}_{0.93}O\rightarrow {\mathrm{Fe}}_{2}{O}_{3}$

The valence factor of ${\mathrm{Fe}}_{0.93}O$ , $\mathrm{nf}=(3-\frac{200}{93})\times 0.93$

$\mathrm{nf}=0.79$

Hence, the equivalent weight $=\frac{\mathrm{Molecular}\mathrm{weight}}{0.79}$

$B:2x+(0.93-x)\times 3=2$

$x=0.79$

${\mathrm{Fe}}^{2+}=0.79,{\mathrm{Fe}}^{3+}=0.14$

$D:%{\mathrm{Fe}}^{2+}=\frac{0.79}{0.93}\times 100=85%;{\mathrm{Fe}}^{3+}=15%$

JEE Main 2023 — Chemistry Physical Chemistry

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JEE Main 2023 — Chemistry Physical Chemistry

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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

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