Volatility (chemistry) Volatility (chemistry) In chemistry and physics, volatility is quantified by the tendency of a substance to vaporize. Volatility is directly related to a substance's vapor pressure. At a given temperature, a substance with higher vapor pressure vaporizes more readily than a substance with a lower vapor pressure. The term is primarily written to be applied to liquids; however, it may be used to describe the process of sublimation which is associated with solid substances, such as dry ice (solid carbon dioxide) and osmium tetroxide (OsO), which can change directly from the solid state to a vapor, without becoming liquid. The
Solidus (chemistry) not coincide. If a gap exists between the solidus and liquidus it is called the freezing range, and within that gap, the substance consists of a mixture of solid and liquid phases (like a slurry). Such is the case, for example, with the olivine (forsterite-fayalite) system. In eutectic mixtures the solidus and liquidus temperatures coincide at a point known as the eutectic point. At the eutectic point, the solid congruently melts (i.e., melts completely). Solidus (chemistry) In chemistry, materials science, and physics, the solidus is the locus of temperatures (a curve on a phase diagram) below which a given substance