Solubility is an equilibrium position, whereas \(K_{\text {sp }}\) is an equilibrium constant. Explain the difference.

Solubility is a measure of the maximum amount of a solute that can dissolve in a specific amount of solvent (usually water) at a given temperature and pressure to form a saturated solution. It is often expressed in units of grams per 100 grams of solvent or in moles per liter of solution (molarity).

The solubility product constant (\(K_{sp}\)) is an equilibrium constant for the dissolution of a sparingly soluble ionic compound in water. It is the product of the equilibrium concentrations of the ions in the solution, each raised to the power of their respective stoichiometric coefficients in the balanced dissolution equation. The larger the \(K_{sp}\) value, the more soluble the compound is in water.

Solubility and \(K_{sp}\) are related yet distinct concepts. Solubility is a measurement that describes how much solute can dissolve in a given amount of solvent, while the \(K_{sp}\) provides insight into the extent of the equilibrium of the dissolution process. Specifically, the solubility provides a quantitative value of how much solute can be dissolved in the solvent, whereas the \(K_{sp}\) is a dimensionless constant that describes the equilibrium position of the dissolution reaction. The greater the \(K_{sp}\), the more the equilibrium favors dissolution of the solute in the solvent. The more soluble a substance is, the higher its concentration in the saturated solution, and thus the higher the \(K_{sp}\) of the substance. In summary, solubility is a measure of the maximum amount of solute that can dissolve under specific conditions, while \(K_{sp}\) is an equilibrium constant that describes the intrinsic solubility properties of a substance. These two concepts are related but are different ways of describing the dissolution behavior of a solute in a solvent.