Question

The Hydration energy of $M{g}^{2+}$ is larger than that of:

• A. $A{l}^{3+}$
• B. $C{a}^{2+}$
• C. $B{e}^{2+}$
• D. Can't be predicted

Answer 1

The correct option is B $C{a}^{2+}$

Hydration energy is the amount of energy released upon the solvation of the ion in water.

Hydration energy depends on the charge on the ion and the ionic radius. Higher the charge and smaller the size, greater is the hydration energy. Since $M{g}^{2+}$ has a smaller size and same charge in comparison with $C{a}^{2+}$, it has a higher hydration energy than $C{a}^{2+}$ among the four.