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The sublimation that occurs at the solid-gas boundary (critical sublimation point) (corresponding to boiling in vaporization) may be called rapid sublimation, and the substance sublimes rapidly. The words "gradual" and "rapid" have acquired special meanings in this context and no longer describe the rate of sublimation.
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.
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 .
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. Another example is when frost forms on a leaf. For deposition to occur, thermal energy must be removed from a gas.
Outgassing is a challenge to creating and maintaining clean high-vacuum environments.NASA and ESA maintain lists of materials with low-outgassing properties suitable for use in spacecraft, as outgassing products can condense onto optical elements, thermal radiators, or solar cells and obscure them.
For example, dry ice has a sublimation temperature of −78.5 °C which is equivalent to −109.3 °F. [97] On the absolute Kelvin scale this temperature is 194.6 K . No body of matter can be brought to exactly 0 K (the temperature of the ideally coldest possible body) by any finite practicable process; this is a consequence of the third law of ...
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.