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Notable examples include sublimation of dry ice at room temperature and atmospheric pressure, and that of solid iodine with heating. The reverse process of sublimation is deposition (also called desublimation), in which a substance passes directly from a gas to a solid phase, without passing through the liquid state. [4]
One example of deposition is the process by which, in sub-freezing air, water vapour changes directly to ice without first becoming a liquid. This is how frost and hoar frost form on the ground or other surfaces, including leaves. For deposition to occur, thermal energy must be removed from a gas.
Sublimation is the process of changing of any substance (usually on heating) from a solid to a gas (or from gas to a solid) without passing through liquid phase. In terms of purification - material is heated, often under vacuum, and the vapors of the material are then condensed back to a solid on a cooler surface.
This diagram shows the nomenclature for the different phase transitions. In physics, chemistry, and other related fields like biology, a phase transition (or phase change) is the physical process of transition between one state of a medium and another.
In thermodynamics, the enthalpy of sublimation, or heat of sublimation, is the heat required to sublimate (change from solid to gas) one mole of a substance at a given combination of temperature and pressure, usually standard temperature and pressure (STP). It is equal to the cohesive energy of the solid.
Freeze-dried strawberries. Freeze drying, also known as lyophilization or cryodesiccation, is a low temperature dehydration process [1] that involves freezing the product and lowering pressure, thereby removing the ice by sublimation. [2]
Sublimation or sublimate may refer to: Sublimation, by Canvas Solaris, 2004; Sublimation (phase transition), directly from the solid to the gas phase; Sublimation (psychology), a mature type of defense mechanism; Sublimate of mercury, or Mercury(II) chloride; Volcanic sublimate, a product of deposition from vapors around volcanic vents
A sublimatory [1] [2] or sublimation apparatus is equipment, commonly laboratory glassware, for purification of compounds by selective sublimation. In principle, the operation resembles purification by distillation , except that the products do not pass through a liquid phase .