Why is solubility dependent on lattice enthalpy?

The correct understanding of why solubility is dependent on lattice enthalpy lies in the concept of ionic solids and their dissolution in solvents, particularly water. Lattice enthalpy refers to the amount of energy that is released when gaseous ions form an ionic solid or, conversely, the energy required to break the ionic solid into its constituent ions in the gaseous state.

When an ionic compound dissolves in a solvent, the ions must be separated from their fixed positions in the crystal lattice. This process requires considerable energy to overcome the strong electrostatic forces that hold the ions together, which is quantitatively described by the lattice enthalpy. If the lattice enthalpy is very high, it means that a large amount of energy is needed to break the ionic bonds, making it less likely for the solid to dissolve in the solvent.

Therefore, the greater the lattice enthalpy, the more difficult it is for the solid to dissolve, leading to lower solubility. Conversely, if the lattice enthalpy is relatively low, the ions can be more easily separated and solvated by the solvent molecules, resulting in higher solubility. In summary, the relationship between lattice enthalpy and solubility is a critical factor in