Question

Which of the following is arranged in the increasing order of hydration energy?

• A. $C{u}^{2+}<F{e}^{3+}<F{e}^{2+}<A{l}^{3+}$
• B. $F{e}^{2+}<C{u}^{2+}<F{e}^{3+}$< $A{l}^{3+}$
• C. $A{l}^{3+}<F{e}^{3+}<F{e}^{2+}<C{u}^{2+}$
• D. $F{e}^{3+}<A{l}^{3+}<C{u}^{2+}<F{e}^{2+}$

Answer 1

The correct option is B $F{e}^{2+}<C{u}^{2+}<F{e}^{3+}$< $A{l}^{3+}$

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

Hydration energy depends on the charge on the ion and the ionic radius. Higher the charge, smaller the size, greater is the hydration energy. Considering both the charge and the size, hydration energy will follow the order $F{e}^{2+}<C{u}^{2+}<F{e}^{3+}<A{l}^{3+}$
and the ioinic size order is $F{e}^{2+}>C{u}^{2+}>F{e}^{3+}>A{l}^{3+}$