How would you explain the following observations ? Beo is almost insoluble but BeSO_(4) in soluble in water.

How would you explain the following observations ? Beo is almost inso

1.	How would you explain the following observations ? Beo is almost insoluble but BeSO_(4) in soluble in water.
Answer» Solution : BeO is almost insoluble in water and`BeSO_(4)` is soluble in water. `Be^(2+)`is a small cation with a high polarising POWER and `O^(2-)`is a small anion. The SIZE compatibility of `Be^(2+)` and `O^(2-)`is high. Therefore, the lattice energy released during their formation is alsovery high. When BeO is dissolved in water, the hydration energy of its ions is not sufficient to overcome the high lattice energy. Therefore, BeO is insoluble in water. On the other hand, `SO_(4)^(2-)`ion is a LARGE anion. Hence, `Be^(2)+`can easily polarize `SO_(4)^(2-)` ions, making `BeSO_(4)` unstable. Thus, the lattice energy of `BeSO_(4)` is not very high and so it is soluble in water.