Consider the solubility of alkaline earth metal fluorides in water. What is the observed trend from — s Block Elements Chemistry Question

💡 Solution & Explanation

Unlike sulphates and carbonates where solubility decreases down the group, the solubility of fluorides generally INCREASES down the group ($MgF_2 < CaF_2 < SrF_2 < BaF_2$). Because $F^-$ is a small anion, the lattice energy drops very rapidly as cation size increases, overcoming the drop in hydration energy.