Question

Hydration Energy of $M{g}^{2+}$ is lower than that of:

• A. $N{a}^{+}$
• B. $C{a}^{2+}$
• C. $A{l}^{3+}$
• D. $B{e}^{2+}$

Answer 1

Answer: (C), (D)

The correct options are
C $A{l}^{3+}$
D $B{e}^{2+}$

Hydration Energy $\propto$ $\frac{Chargeonion}{Sizeofion}$
$\left(a\right)$ As, Charge on $M{g}^{2+}$ > $N{a}^{+}$ and size of $N{a}^{+}$ is more than size of $M{g}^{2+}$
$\therefore$ Hydration Energy of $M{g}^{2+}>N{a}^{+}$.

$\left(b\right)$ As, Charge on $M{g}^{2+}$ = $C{a}^{2+}$ and size of $C{a}^{2+}$ is more than size of $M{g}^{2+}$
$\therefore$ Hydration Energy of $M{g}^{2+}>C{a}^{2+}$.

$\left(c\right)$ As, Charge on $A{l}^{3+}$ > $M{g}^{2+}$ and size of $A{l}^{3+}$ is smaller than size of $M{g}^{2+}$
$\therefore$ Hydration Energy of $M{g}^{2+}<A{l}^{3+}$.

$\left(d\right)$ As, Charge on $B{e}^{2+}$ = $M{g}^{2+}$ and size of $B{e}^{2+}$ is smaller than size of $M{g}^{2+}$
$\therefore$ Hydration Energy of $M{g}^{2+}<B{e}^{2+}$.