JEE Main 2022 — Chemistry Inorganic Chemistry

2022mcqeasy

Which one of the lanthanoids given below is the most stable in divalent form?

Official previous-year question

Held on 28 Jun 2022 · Verified 6 Jul 2026.

Options

A
$\mathrm{Yb}$ (Atomic Number $70$ )
B
$Sm$ (Atomic Number $62$ )
C
$\mathrm{Eu}$ (Atomic Number $63$ )
D
$\mathrm{Ce}$ (Atomic Number $58$ )

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Solution

${\mathrm{Ce}}^{+2}:(\mathrm{xe})4{f}^{2}$

${\mathrm{Eu}}^{+2}:(\mathrm{xe})4{f}^{7}$

${\mathrm{Sm}}^{+2}:(\mathrm{xe})4{f}^{6}$

${\mathrm{Yb}}^{+2}:(\mathrm{xe})4{f}^{14}$

As ${\mathrm{Yb}}^{+2}\mathrm{and}{\mathrm{Eu}}^{+2}$ has completely filled and half filled $4f$ orbital, so they would be the most stable. But among the these two ${\mathrm{Eu}}^{+2}$ is more stable based on reduction potential value.

${E}_{{M}^{3+}/{M}^{2+}}^{^{\circ}}\Rightarrow \begin{matrix}\mathrm{Eu} & \mathrm{Yb} \\ -0.35 & -1.05\end{matrix}$

Hence, due to more reduction potential in $\mathrm{Eu}$ as compared to $\mathrm{Yb}$ , it can concluded that ${\mathrm{Eu}}^{2+}$ is more stable than ${\mathrm{Yb}}^{2+}$ .

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JEE Main 2022 — Chemistry Inorganic Chemistry

2022mcqeasy

Which one of the lanthanoids given below is the most stable in divalent form?

Official previous-year question

Held on 28 Jun 2022 · Verified 6 Jul 2026.

Options

A
$\mathrm{Yb}$ (Atomic Number $70$ )
B
$Sm$ (Atomic Number $62$ )
C
$\mathrm{Eu}$ (Atomic Number $63$ )
D
$\mathrm{Ce}$ (Atomic Number $58$ )

Did you get this right?

Solution

${\mathrm{Ce}}^{+2}:(\mathrm{xe})4{f}^{2}$

${\mathrm{Eu}}^{+2}:(\mathrm{xe})4{f}^{7}$

${\mathrm{Sm}}^{+2}:(\mathrm{xe})4{f}^{6}$

${\mathrm{Yb}}^{+2}:(\mathrm{xe})4{f}^{14}$

${E}_{{M}^{3+}/{M}^{2+}}^{^{\circ}}\Rightarrow \begin{matrix}\mathrm{Eu} & \mathrm{Yb} \\ -0.35 & -1.05\end{matrix}$

Hence, due to more reduction potential in $\mathrm{Eu}$ as compared to $\mathrm{Yb}$ , it can concluded that ${\mathrm{Eu}}^{2+}$ is more stable than ${\mathrm{Yb}}^{2+}$ .

JEE Main 2022 — Chemistry Inorganic Chemistry

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JEE Main 2022 — Chemistry Inorganic Chemistry

Options

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Solution

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JEE Main Inorganic Chemistry in other years

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Physical Chemistry

Organic Chemistry

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