insolubile

In Italian, insolubile is an adjective describing a substance that cannot be dissolved in a particular solvent under defined conditions; in English the equivalent word is insoluble. Insolubility is not absolute: many substances are insoluble in certain solvents but may dissolve in others, and solubility often changes with temperature and pressure. In chemistry, solubility describes the maximum amount of a substance that can dissolve in a solvent to form a saturated solution, typically quantified by the solubility product constant (Ksp) for sparingly soluble salts. Substances with very low Ksp values are regarded as insoluble under ordinary conditions.

Typical insoluble or sparingly soluble substances in water include calcium carbonate, barium sulfate, silver chloride, and silica. These compounds do not appreciably increase the concentration of dissolved ions in water, leading to precipitation or persistence as solid particles.

Factors affecting insolubility: solvent polarity, hydrogen bonding, temperature, and pressure; the principle that like dissolves like guides solubility behavior. For gases, solubility often decreases with rising temperature; for solids in liquids, solubility can increase or decrease with temperature depending on the substance. pH can influence solubility of metal hydroxides or amines.

Applications and implications: the insolubility of a compound affects formulation of medicines, environmental mobility of contaminants, mining and mineral processing, and geology. Strategies to overcome insolubility include salt formation, use of co-solvents, surfactants, or particle-size reduction.