Chemistry - PERIODIC TABLE Question with Solution | TestHub

Hydration energy is inversely proportional to ionic size and directly proportional to charge. All given orders are correct. Concepts: 1. Hydration energy: Energy released when 1 mole of gaseous ions dissolves in water. 2. Factors affecting hydration energy:

a. Ionic charge: Higher charge leads to stronger attraction to water dipoles, thus higher hydration energy.

b. Ionic size: Smaller ionic size leads to higher charge density and stronger attraction to water dipoles, thus higher hydration energy. Analysis of options:

A. ${\mathrm{F}}_{(aq.)}^{-}>{\mathrm{Cl}}_{(aq.)}^{-}$: Correct. F⁻ is smaller than Cl⁻.

B. ${\mathrm{Li}}_{(aq.)}^{+}>{\mathrm{Na}}_{(aq.)}^{+}$: Correct. Li⁺ is smaller than Na⁺.

C. ${\mathrm{Al}}_{(aq.)}^{+3}>{\mathrm{Mg}}_{(aq.)}^{+2}$: Correct. Al³⁺ has a higher charge and smaller size than Mg²⁺. Since all options show correct orders of hydration energy, the incorrect order is "None of these".