Vaporgas

Vaporgas is a term occasionally used to refer to the gaseous phase of a substance when it exists in equilibrium with a condensed phase, such as a liquid or a solid. In this sense, vaporgas is the vapor formed by vaporization and is governed by temperature, pressure, and composition. The term is not a formal science designation on its own, but it can appear in discussions of phase transitions, evaporation, and distillation.

In thermodynamics, the vapor (or vapour) of a substance is the gas that coexists with its condensed form at a given temperature. The broader term gas describes matter in the gaseous state across a wider range of conditions. Vaporgas emphasizes the relationship between the gas phase and its saturated pressure, i.e., the vapor pressure at a particular temperature.

Key properties include vapor pressure, temperature, and the tendency of a substance to condense or evaporate. At low to moderate pressures, the vaporgas of many substances behaves approximately like an ideal gas, while deviations occur at higher pressures or with heavy molecules. The Clausius–Clapeyron relation describes how vapor pressure changes with temperature for many liquids.

Vaporgas is produced and studied in processes such as evaporation, boiling, distillation, and sublimation. It is relevant in fields like chemical engineering, atmospheric science, and vacuum technology. Measurement and control of vaporgas properties are important for designing reactors, separations, and safety systems. Care should be taken that the term is used with context, since vapour or vapor generally suffices to describe the gas-phase portion of a substance.