Question

Which of the following has the highest hydration energy?

• A. Be+2
• B. Mg+2
• C. Ca+2
• D. Ba+2

Answer 1

Answer: (A)

Be+2

Answer 2

The correct option is (A): Be$^{2+}$
Highly charged and smaller-sized metal ions have higher hydration energy. The hydration energy for the compact and charged ions is greater than the large-sized charged ions, in the alkaline earth metals. Therefore, the order of hydration energy in this group is Be$^{2+}$>Mg$^{2+}$ >Ca$^{2+}$>Sr$^{2+}$>Ba$^{2+}$.