solvent, constituent of a solution that acts as a dissolving agent. In solutions of solids or gases in a liquid, the liquid is the solvent. In all other solutions (i.e., liquids in liquids or solids in solids) the constituent that is present in larger quantity is considered the solvent. The most familiar and widely used solvent is water. Other compounds valuable as solvents because they dissolve materials that are insoluble or nearly insoluble in water are acetone, alcohol, benzene (or benzol), carbon disulfide, carbon tetrachloride, chloroform, ether, ethyl acetate, furfural, gasoline, toluene, turpentine, and xylene (or xylol). Solvents are often organic compounds. They may be divided into polar and nonpolar types. Polar solvents, of which water is an example, have molecules whose electric charges are unequally distributed, leaving one end of each molecule more positive than the other. Nonpolar solvents, of which carbon tetrachloride is an example, have molecules whose electric charges are equally distributed.