Vapor pressure inorganic compounds

Heats of vaporization of inorganic compounds may be determined in the same way as for organic compounds (Section 7.4), although the Knudsen vapour pressure method has perhaps been used more for inorganic compounds. No further discussion is called for here. 

This method is particularly valuable in separating volatile from nonvolatile compounds such as salts or other inorganic compounds. It is also very valuable for working with bicyclic and other rather symmetrical molecules, which usually have rather high vapor pressures. These compounds may often be efiiciently separated from other less volatile reaction products. 

Table 5.8 Vapor Pressures of Various Inorganic Compounds 5.31...

Most inorganic mercury compounds have very low vapor pressures, and generally do not contribute to high mercury vapor readings. MetaUic mercury is the most potent and troublesome in this respect. Organic mercurials also contribute to mercury vapor readings, possibly by virtue of the presence of extremely small amounts of metallic mercury present as an impurity. 

TABLE 2-7 Vapor Pressures of Inorganic Compounds/ up to 1 atm Continued)... 

A general reference often consulted today for the physical and chemical properties of common chemicals is Lange s Handbook of Chemistry (Dean 1999), which lists many chemical compounds and their most important properties. It is organized into separate chapters of Physical constants of organic molecules with 4300 compounds and Physical constants of inorganic molecules, and lists each compound alphabetically by name. Some of these properties are very sensitive to temperature, but less sensitive to pressure, and they are listed as tables, or more compactly as equations of the form /(T) for example, liquid heats of evaporation, heat capacities of multi-atom gases, vapor pressures over liquids, liquid and solid solubilities in liquids, and liquid viscosities. Some of these properties are sensitive both to temperature and pressure. 

Foster Wheeler Development Corporation (FWDC) has designed a transportable transpiring wall supercritical water oxidation (SCWO) reactor to treat hazardous wastes. As water is subjected to temperatures and pressures above its critical point (374.2°C, 22.1 MPa), it exhibits properties that differ from both liquid water and steam. At the critical point, the liquid and vapor phases of water have the same density. When the critical point is exceeded, hydrogen bonding between water molecules is essentially stopped. Some organic compounds that are normally insoluble in liquid water become completely soluble (miscible in all proportions) in supercritical water. Some water-soluble inorganic compounds, such as salts, become insoluble in supercritical water. 

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