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
Equivalent (chemistry) Equivalent (chemistry) An equivalent (symbol: equiv) is the amount of a substance that reacts with (or is "equivalent" to) an arbitrary amount of another substance in a given chemical reaction. It is an archaic unit of measurement that was used in chemistry and the biological sciences in the era before researchers knew how to determine the chemical formula for a compound. The mass of an equivalent is called its equivalent weight. In a more formal definition, the "equivalent" is the amount of a substance needed to do one of the following: By this definition, an "equivalent" is the number of