The hydroxides and carbonates of sodium and potassium are easily soluble in water,while the corresponding salts of magnesium and calcium are sparingly soluble in water. Explain.

(N/A) The solubility of ionic compounds in water is determined by the balance between lattice energy and hydration energy.
For $Na^+$ and $K^+$ salts,the lattice energy is relatively low due to the larger size of the cations,which is easily overcome by the hydration energy released upon dissolution.
In contrast,$Mg^{2+}$ and $Ca^{2+}$ are smaller and carry a higher charge $(+2)$,resulting in significantly higher lattice energies for their carbonates and hydroxides.
Since the lattice energy of $Mg$ and $Ca$ salts is much higher than the hydration energy,they are only sparingly soluble in water.