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

How would you explain the following observation? BeO is almost insolub

1.	How would you explain the following observation? BeO is almost insoluble but BeSO_(4) is soluble in water.
Answer» Solution :(i) BeO is almost insoluble in water because `Be^(2+)` is a small cation with high POLARISING power and `O^(2-)` is small anion. `therefore` the LATTICE energy very high. When BeO is dissolved in water, the hydration energy of its ions is not sufficient to overcome high lattice energy. (II) On the other hand, `Be^(2+)` is a small cation and `SO_(4)^(2-)` is a large anion. Hence `Be^(2+)` can EASILY polarize `SO_(4)^(2-)` ions, making `BeSO_(4)` unstable the lattice energy of `BeSO_(4)` is not very high and so it is soluble in water.