dissolvents

Dissolvent, more commonly called a solvent, is a substance—usually a liquid—that dissolves another substance (the solute) to form a solution. The dissolvent is the medium in which dissolution occurs; the solute is the species being dissolved. The term dissolvent is used in some contexts but is largely synonymous with solvent.

Solvents are classified by polarity and hydrogen-bonding ability. Polar protic solvents such as water and alcohols can donate hydrogen bonds; polar aprotic solvents such as acetone, dimethyl sulfoxide (DMSO), and acetonitrile can dissolve many salts and organic compounds without donating protons; nonpolar solvents such as hexane or toluene dissolve nonpolar substances. Many solvents are miscible with water to varying degrees.

Solubility depends on temperature, pressure (for gases), and intermolecular interactions. The principle "like dissolves like" summarizes tendencies: polar solvents dissolve polar solutes; nonpolar solvents dissolve nonpolar solutes. Solvent selection often uses solubility parameters or empirical screening.

Applications include chemical synthesis as reaction media, extraction and purification, formulation of pharmaceuticals and inks, and cleaning and degreasing. In analytical chemistry, solvents are chosen for chromatography and spectroscopic preparation.

Safety and environment: many solvents are flammable or toxic; exposure can be harmful; disposal and environmental impact are regulated. Preferred solvents are sought to minimize hazards, and greener solvents are increasingly used.

Etymology: The word dissolvent derives from dissolvere; in modern English, solvent is standard, though dissolvent appears in technical or older literature.