Why is NaPo4 soluble in water but NiCrO4 not?

Answer 1

Na₄PO₄ is soluble in water due to its ionic nature and the strong interaction between its sodium ions (Na⁺) and water molecules, which facilitates its dissociation into constituent ions. In contrast, NiCrO₄ is less soluble because it has a more substantial lattice energy due to the presence of larger metal ions and less favorable hydration interactions, making it harder for water molecules to break apart its ionic structure. Thus, the difference in solubility is primarily influenced by the balance of lattice energy and hydration energy for each compound.