Question

$BeO$ is insoluble but $BaO$ is soluble as:

• A. lattice energy of $BeO$ is higher than $BaO$ due to small size of $B{e}^{2+}$ ion and its covalent nature
• B. hydration energy of $BeO$ is lower than $BaO$ due to small size $B{e}^{2+}$ ion
• C. $BeO$ is amphoteric in nature while $BaO$ is basic
• D. $BeO$ forms hydrated salts hydrated salts while $BaO$ form anhydrous salts

Answer 1

Answer: (A)

lattice energy of $BeO$ is higher than $BaO$ due to small size of $B{e}^{2+}$ ion and its covalent nature

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, sulphate ion is a large anion. Thus, the lattice energy of $BeS{O}_4$ is not very high and so it is soluble in water. Hence, Lattice energy of $BeO$ is higher than $BaO$ due to small size of ${Be}^{2+}$ and its covalent nature.