Vapor pressure organic compounds

The required condensation temperature can then be obtained from a vapor pressure-temperature chart for the specific organic compound. Vapor pressure data for foiu typical VOCs are given in Figure 16-16. For example, if the gas contains 13,000 ppmv styrene (yj = 0.013) and 90% removal is desired (E - 0.9), the above equations yield a value for y of... 

Figure 16-16. Vapor pressures of four typical volatile organic compounds = vapor pressure of compound (mm Hg), Tcm = condensaftlon temperature ( F). U.S. EPA Handbook, 1991)...

Volatile organic compounds Vapor pressure polarization coefficient Vinyltrimethylsilicon/carbon tetrailuoride X-ray photoelectron spectroscopy Zirconia... 

Organic Compounds Chemicals that contain carbon. Volatile organic compounds vaporize at room temperature and pressure. They are found in many indoor sources, including many common household products and building materials. 

The vapor pressure of 2,4-DNP is 1.49x1 O 5 mm Hg at 18 °C (Mabey et al. 1981). Organics with vapor pressures of 10" to 10" mm Hg at ambient temperature should exist partly in the vapor and partly in the particulate phase in the atmosphere (Eisenreich et al. 1981). Nitrophenols were detected experimentally in the particulate phase in air (Nojima et al. 1983), although the method used to collect atmospheric particulate matter was not suitable for collecting vapor-phase dinitrophenols. The distance of atmospheric transport of dinitrophenols will depend on atmospheric residence times. The residence time of dinitrophenols, based on the estimated rates of various reactions, is long enough to allow atmospheric transport (see Section 5.3.2.1). The removal and transport of atmospheric dinitrophenols to land and water by physical processes, such as wet and dry deposition, will depend on the physical states of these compounds in the atmosphere. Since dinitrophenols have been detected in rain, snow, and fog (Alber et al. 1989 Capel et al. 1991 ... 

The Vapor Pressure of Environmentally Significant Organic Chemicals Vapor pressures are provided for polynuclear aromatic hydrocarbons, PCBs, chlorinated dioxins and furans, and some pesticides. Values for each compound are compiled and referenced. 

Volatility is a function of the vapor pressure of a compound. Vapor pressures at a particular temperature can vary over many orders of magnitude. Of common organic liquids, diethyl ether has one of the highest vapor pressures, whereas those of polychlorinated biphenyls (PCBs) are very low. When a volatile liquid is present in soil or in water, its water solubihty also determines how well it evaporates. For... 

Jordan, T. E. "Vapor Pressure of Organic Compounds," Interscience, New York, 1954. 

Compilation of vapor-pressure data for organic compounds data are correlated with the Antoine equation and graphs are presented. 

Compilation of vapor pressures of organic and related compounds to one atmosphere. 

Table 5.9 Vapor Pressures of Various Organic Compounds 5.39...

At normal pressures (around atmospheric) and up to about 250°C (approaching the limit of thermal stability for most organic compounds), a volatile substance can be defined as one that can be vaporized by heat between ambient temperature (10 to 30°C) and 200 to 250°C. All other substances are nonvolatile. 

Volatilization. The susceptibility of a herbicide to loss through volatilization has received much attention, due in part to the realization that herbicides in the vapor phase may be transported large distances from the point of application. Volatilization losses can be as high as 80—90% of the total applied herbicide within several days of application. The processes that control the amount of herbicide volatilized are the evaporation of the herbicide from the solution or soHd phase into the air, and dispersal and dilution of the resulting vapor into the atmosphere (250). These processes are influenced by many factors including herbicide application rate, wind velocity, temperature, soil moisture content, and the compound s sorption to soil organic and mineral surfaces. Properties of the herbicide that influence volatility include vapor pressure, water solubility, and chemical stmcture (251). 

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. 

Organic compounds of bromine usually resemble their chlorine analogues but have higher densities and lower vapor pressures. The bromo compounds are more reactive toward alkaUes and metals brominated solvents should generally be kept from contact with active metals such as aluminum. On the other hand, they present less fire hazard one bromine atom per molecule reduces flammabiUty about as much as two chlorine atoms. 

Pure carbon disulfide is a clear, colorless Hquid with a deHcate etherHke odor. A faint yellow color slowly develops upon exposure to sunlight. Low-grade commercial carbon disulfide may display some color and may have a strong, foul odor because of sulfurous impurities. Carbon disulfide is slightly miscible with water, but it is a good solvent for many organic compounds. Thermodynamic constants (1), vapor pressure (1,2), spectral transmission (3,4), and other properties (1,2,5—7) of carbon disulfide have been deterrnined. Principal properties are Hsted in Table 1. 

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