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White or colorless crystalline solid, hygroscopic: Odor: Odorless Density: 1.519 g/cm 3 [1] Melting point: 338 °C (640 °F) Sublimation ... Ammonium chloride is an ...
The term sublimation refers specifically to a physical change of state and is not used to describe the transformation of a solid to a gas in a chemical reaction. For example, the dissociation on heating of solid ammonium chloride into hydrogen chloride and ammonia is not sublimation but a chemical reaction.
Conditions are so chosen that the solid volatilizes and condenses as a purified compound on a cooled surface, leaving the non-volatile residual impurities or solid products behind. The form of the cooled surface often is a so-called cold finger which for very low-temperature sublimation may actually be cryogenically cooled.
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.
Ammonium fluoride is the inorganic compound with the formula NH 4 F. It crystallizes as small colourless prisms, having a sharp saline taste, and is highly soluble in water. It crystallizes as small colourless prisms, having a sharp saline taste, and is highly soluble in water.
Mercury(II) chloride (or mercury bichloride [citation needed], mercury dichloride), historically also known as sulema or corrosive sublimate, [2] is the inorganic chemical compound of mercury and chlorine with the formula HgCl 2, used as a laboratory reagent.
The three major cyclophosphazene products resulting from the reaction of phosphorus pentachloride and ammonium chloride. Purification by sublimation gives mainly the trimer and tetramer. Slow vacuum sublimation at approximately 60 °C affords the pure trimer free of the tetramer. [6]
Salammoniac, [2] also sal ammoniac or salmiac, is a rare naturally occurring mineral composed of ammonium chloride, NH 4 Cl. It forms colorless, white, or yellow-brown crystals in the isometric-hexoctahedral class. It has very poor cleavage and is brittle to conchoidal fracture.