hochflüchtige

hochflüchtige is a German term used in scientific contexts to describe substances that readily vaporize under ordinary conditions. The adjective is applied to solvents and small organic molecules with high vapor pressures and low boiling points, indicating a tendency to exist as vapour rather than as a liquid at typical temperatures.

Key properties include high vapor pressure at a given temperature, low boiling point, and rapid evaporation. Such substances can pose inhalation and fire hazards, and they often dominate air-borne emissions in industrial settings. Their volatility also affects handling, storage, and safety procedures, requiring measures such as adequate ventilation and containment to minimize exposure.

Measurement and regulation: volatility is commonly assessed through vapor pressure measurements at 25 °C and by the boiling point. In addition, Henry's law constants and vapor–liquid equilibrium data are used in modeling. National and international definitions of highly volatile compounds may vary, particularly in the context of volatile organic compounds (VOCs) regulations.

Examples of hochflüchtige substances include common solvents such as acetone, methanol, ethanol, and diethyl ether, as well as many light hydrocarbons. By contrast, substances with higher boiling points and lower vapor pressures are described as less volatile.

Etymology: hoch means high, flüchtig means volatile or fugitive in German. The term is widely used in German-language chemistry and environmental literature to distinguish substances by their tendency to vaporize.