Alkenes flammable liquids

Benzene is a colorless, flammable liquid obtained chiefly from petroleum and coal tar. Perhaps the most remarkable chemical property of benzene is its relative inertness. Although it has the same empirical formula as acetylene (CH) and a high degree of unsaturation, it is much less reactive than either ethylene or acetylene. The stability of benzene is the result of electron delocalization. In fact, benzene can be hydrogenated, but only with difficulty. The following reaction is carried out at significantly higher temperatures and pressures than are similar reactions for the alkenes ... 

The first flammable liquid in the aUcene family is pentene. Because it is an alkene, it has a double bond in the compound. Pentene has a boiling point of 86°F, a flash point of 0°F, a flammable range of 1.5 to 8.7%, and an ignition temperature of 527°F. The structure and formula for pentene is shown in Figure 5.35. 

Titanium tetrachloride is a moisture-sensitive, highly flammable liquid reacting violently with water (34). It is a strong Lewis acid capable of promoting Diels-Alder reactions (35) and induces the addition of silyl enol ethers and allyl silanes to carbonyl compounds and derivatives (34r-36). It is a less commonly used catalyst in Friedel-Crafts reactions but very useful for the acylation of activated alkenes and in the Fries rearrangement. 

Flammable liquids may undergo a chemical reaction called polymerization, in which a large number of simple molecules, called monomers, combine to form long-chained molecule called a polymer. This process is used under controlled conditions to create plastics (see Figure 5.17). Alkene hydrocarbon compounds and hydrocarbon derivatives, such as aldehydes, alkyl halides, and esters, and the aromatic hydrocarbon styrene may undergo polymerization. There are other monomers that are flammable and can polymerize, but their primary hazard is poison. Monomers can be flammable liquids, flammable gases, and poisons. 

Alkenes — Also known as olefins, and denoted as C H2 the compounds are unsaturated hydrocarbons with a single carbon-to-carbon double bond per molecule. The alkenes are very similar to the alkanes in boiling point, specific gravity, and other physical characteristics. Like alkanes, alkenes are at most only weakly polar. Alkenes are insoluble in water but quite soluble in nonpolar solvents like benzene. Because alkenes are mostly insoluble liquids that are lighter than water and flammable as well, water is not used to suppress fires involving these materials. Because of the double bond, alkenes are more reactive than alkanes. 

Alkenes are insoluble in water but quite soluble in nonpolar solvents like benzene. Because alkenes are mostly insoluble liquids that are lighter than water and flammable as well, water is not used to suppress fires involving these materials. Because of the double bond, alkenes are more reactive than alkanes. 

Propylene, CjH (propene), has a boiling point of -53°F. The flammable range of propylene is 2 to 11%. The vapor density is 1.46, which is heavier than air. The four-digit UN identification number is 1077. The NFPA 704 designation is health 1, flammability 4, and reactivity 1. It is not toxic, but can be an asphyxiant gas by displacing the oxygen in the air. It is usually shipped as a pressurized liquid in cylinders, tank cars, and tank barges. The structure for propylene is shown in the Alkene section of this chapter. 

Isobutylene (methylpropene) is a monounsaturated hydrocarbon with 4 carbon atoms. Under normal conditions it is a colourless, highly flammable gas (mixtures with air between 1.8 and 8.8 vol% at 20 °C can lead to explosions), and it has the characteristic alkene, petroleum-like scent. Isobutene is soluble in organic solvents (like ether, alcohol and hydrocarbons), but almost insoluble in water (0.263 g/L at 25°). It has no corrosive properties and has a low level of acute toxicity (still, extensive exposure should be avoided) (Industries E 2010 Liquide A 2013 Obenaus et al. 2000). 

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