What are the Properties of Solvents?
In general, chlorinated solvents, as pure liquids, have relatively high densities, vapor pressures, and solubilities. In ground water, they also have relatively long half-lives. All solvents considered here have densities greater than 1. This means that they are denser than water and that releases of pure solvents can penetrate the water table (fig. 27). The relatively high vapor pressures of the four solvents means that these compounds can volatilize when spilled onto a surface or exposed to the atmosphere. The aqueous solubilities of the four solvents also generally are high. (96) Consequently, some mass of solvents exposed to land surfaces can move in solution to the water table. Finally, the biotic half-lives of solvents in ground water are longer than those of other commonly used VOCs, like the gasoline hydrocarbons. (97) This means that solvents biodegrade slowly and therefore can persist for long periods of time in certain aquifers. For more highly chlorinated molecules, the bio
