Vapor pressure diethyl ether

Ethers are relatively uncommon atmospheric pollutants, although the flammability hazard of diethyl ether vapor in an enclosed work space is well known. In addition to aliphatic ethers, such as dimethyl ether and diethyl ether, several alkenyl ethers, including vinylethyl ether, are produced by internal combustion engines. Methyltertiarybutyl ether, MTBE, became tiie octane booster of choice to replace tetraethyllead in gasoline. Because of its widespread distribution, MTBE has the potential to be an air pollutant, although its hazard is limited by its low vapor pressure. Largely because of its potential to contaminate water, MTBE was proposed for phaseout by both the state of California and the U.S. Environmental Protection Agency in 1999. Ethers are relatively unreactive and not as water-soluble as the lower alcohols or carboxylic acids. 

Anionic polymerization of vinyl monomers can be effected with a variety of organometaUic compounds alkyllithium compounds are the most useful class (1,33—35). A variety of simple alkyllithium compounds are available commercially. Most simple alkyllithium compounds are soluble in hydrocarbon solvents such as hexane and cyclohexane and they can be prepared by reaction of the corresponding alkyl chlorides with lithium metal. Methyllithium [917-54-4] and phenyllithium [591-51-5] are available in diethyl ether and cyclohexane—ether solutions, respectively, because they are not soluble in hydrocarbon solvents vinyllithium [917-57-7] and allyllithium [3052-45-7] are also insoluble in hydrocarbon solutions and can only be prepared in ether solutions (38,39). Hydrocarbon-soluble alkyllithium initiators are used directiy to initiate polymerization of styrene and diene monomers quantitatively one unique aspect of hthium-based initiators in hydrocarbon solution is that elastomeric polydienes with high 1,4-microstmcture are obtained (1,24,33—37). Certain alkyllithium compounds can be purified by recrystallization (ethyllithium), sublimation (ethyllithium, /-butyUithium [594-19-4] isopropyllithium [2417-93-8] or distillation (j -butyUithium) (40,41). Unfortunately, / -butyUithium is noncrystaUine and too high boiling to be purified by distiUation (38). Since methyllithium and phenyllithium are crystalline soUds which are insoluble in hydrocarbon solution, they can be precipitated into these solutions and then redissolved in appropriate polar solvents (42,43). OrganometaUic compounds of other alkaU metals are insoluble in hydrocarbon solution and possess negligible vapor pressures as expected for salt-like compounds. 

Since a vapor pressure of 200 niin Hg is eoiisiderable, the chance of as little as 7.3% of the diethyl ether evaporating to reach the LFL is quite liigh. Those periods of time, such as weekends, when the refrigerator might not be opened, would result in situations of greatest risk. 

Consider the following data for the vapor pressure of diethyl ether, a widely used anesthetic in the early days of surgery. 

Consider an apparatus in which A and B are two 1.00-L flasks joined by a stopcock C. The volume of the stopcock is negligible. Initially, A and B are evacuated, the stopcock C is closed, and 1.50 g of diethyl ether, C2HsOC2H5, is introduced into flask A. The vapor pressure of diethyl ether is 57 Torr at —45°C, 185 Torr at 0.°C, 534 Torr at 25°C, and negligible below — 86°C. (a) If the stopcock is left closed and the flask is brought to equilibrium at —45°C, what will be the pressure of diethyl ether in flask A (b) If the temperature is raised to 25°C, what will be the pressure of diethyl ether in the flask (c) If the temperature of the assembly is returned... 

The state of aggregation of RLi in various solvents has been investigated by a variety of methods. In 1967, West and Waack used a differential vapor pressure technique to study solution colligative properties of RLi . Deviations from ideality indicated that in THF at 25 °C, MeLi and BuLi are tetrameric, PhLi dimeric and benzyllithium monomeric. MeLi was also suggested to be tetrameric in diethyl ether. 

The vapor pressure, p, of a solvent at 25°C is an important quantity and varies considerably among common solvents, some being very volatile (n-pentane and diethyl ether) whereas others are quite nonvolatile (n-hexadecane and dibutyl phthalate). 

C2H 50.CH3-CH3.0C2H6 mw 118.17, color less liq with si ethereal odor, sp gr 0.8417 at 20/20°, fr p -74°, bp 121.4°, fl p 95°F, vapor pressure 9.4mm at 20° partially miscible with w. It can be prepd by reacting the Na alcoholateof an ethyleneglycol ether with ethyl halide or by reacting diethyl sulfate with the ethyleneglycol monoethyl ether (Refs... 

Srivastava, R., G. Natarajan, and B. D. Smith, Total pressure vapor-liquid equilibrium data for binary systems of diethyl ether with acetone, acetonitrile, and methanol. J. Chem. Eng. Data, 31, 89-93 (1986). 

In modern industrial ethyl alcohol plants, the compound is produced in two principal ways (I) by direct hydration of ethylene, or (2) by indirect hydration of ethylene. In the direct hydratiun process. H 0 is added to ethylene in the vapor phase in Lhe presence of a catalyst CH CH 4- H 0 CHiCHiOH. A supported acid catalyst usually is Used. Important factors affecting the conversion include temperature, pressure, the H 0/CH CH ratio, and the purity of (he ethylene, Further, some byproducts are formed by other reactions taking place, a primary side reaction being the dehydration of ethyl alcohol into diethyl ether 2C HjOH (C Hs)jO + HiO. To overcome these problems, a large... 

Liquids with high vapor pressures at ordinary temperatures are said to be volatile. Diethyl ether is highly volatile mercury is not. Solids also exert a vapor pressure, but the vapor pressures of solids are usually much lower than those of liquids because the molecules in a solid are gripped more tightly than they are in a liquid. Nevertheless, solids vaporize in the process called sublimation, which we can observe in the presence of some pungent solids—such as menthol and mothballs. 

FIGURE 8.4 The variation of the vapor pressure of liquids with temperature, for diethyl ether (orange), benzene (red), ethanol (green), and water (blue). The normal boiling point is the temperature at which the vapor pressure is 1 atm (760 Torr). 

Diethyl ether, QHjOQHj, and ethyl methyl ether, C2H5OCH3, form an ideal solution. The vapor pressure of diethyl ether is 185 Torr and that of ethyl methyl ether is 554 Torr at 0.0°C. Calculate the vapor pressure of each of the following solutions and the mole fraction of each substance in the vapor phase above those solutions at 0.0°C (a) 0.75 mol of diethyl ether mixed with 0.50 mol of ethyl methyl ether ... 

Xylene is used as the solvent instead of diethyl ether because of its considerably lower vapor pressure. 

Synonyms ethyl ether, solvent ether, diethyl oxide Formula (C2H5)20 Structure H3C-CH2-0-CH2-CH3 MW 74.14 CAS [60-29-7] used as a solvent used in organic synthesis and as an anesthetic colorless liquid pungent odor sweet burning taste boils at 34.6°C vapor pressure 439 torr at 20°C freezes at -116°C density 0.71 g/mL at 20°C miscible with organic solvents solubility in water 6 g/100 mL forms azeotrope with water (1.3%) extremely flammable narcotic. 

Not likely to occur in ambient air in vapor state the vapor pressure too low. Recommended Method Airborne particles collected on a sorbent cartridge containing polyurethane foam deposited particles extracted with 5% diethyl ether in hexane extract analyzed by GC-ECD recommended air flow 5 L/min sample volume 1000 L. 

Positive deviation from ideal behavior is the usual occurrence for solutions of volatile components, and it results either when solute-solute and solvent-solvent interactions are stronger than solute-solvent interactions or when the addition of the solute breaks up structure (usually due to hydrogen-bonding) in the solvent. A case of mildly positive deviation is illustrated by the diethyl ether-ethanol system shown in Fig. 5. Here, the resulting total vapor pressure of the solution increases continuously as the concentration of the more volatile component (diethyl ether) is increased. 

Just as a solid has a characteristic melting point, a liquid has a characteristic boiling point. At one atmosphere, pure water boils at 100°C, pure ethanol (ethyl alcohol) boils at 78.5°C, and pure diethyl ether boils at 34.6°C. The vapor pressure curves shown in Fig. 

Figure 15.1 Diethyl ether, ethyl alcohol (ethanol), and water vapor pressure curves.

The quantitative nature of the temperature dependence of vapor pressure can be illustrated graphically. Plots of vapor pressure versus temperature for water, ethanol, and diethyl ether are shown in Fig. 16.48(a). Note the nonlinear increase in vapor pressure for all the liquids as the temperature is in-... 

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