How would you explain the following observations ? (i) BeO is almost insoluble but BeSO_(4) is soluble in water (ii) BaO is soluble but BaSO_(4) is insoluble in water (iii) LiI is more soluble than KI in ethanol

How would you explain the following observations ? (i) BeO is almost

1.	How would you explain the following observations ? (i) BeO is almost insoluble but BeSO_(4) is soluble in water (ii) BaO is soluble but BaSO_(4) is insoluble in water (iii) LiI is more soluble than KI in ethanol
Answer» Solution :Both BaO and `BaSO_4` are ionic in nature but the size of `SO_4^(2-)` ions is much larger than that of `O^(2-)` ions. Since a larger ANION STABILISES a larger cation more EFFICIENTLY than a smaller anion stabilises a larger cation, the lattice ENERGY of `BaSO_4` is much higher than that of `BaO`. This is why BaO is SOLUBLE, whereas `BaSO_4` is insoluble in water.