Hydrocarbons Organic compounds that

HYDROCARBONS Organic compounds that contain only hydrogen and carbon. The major sources of hydrocarbons in the atmosphere are vehicle emissions (unburned fuel) and gas leaks. Contributes to acid rain. 

Branched hydrocarbons organic compounds that contain only carbon and hydrogen in... 

Methane, the simplest of all organic compounds, contains one carbon atom. Methane—the main component of natural gas—occurs widely in nature. Like other hydrocarbons—organic compounds that contain only carbon and hydrogen— methane is combustible that is, it burns in the presence of oxygen. Methane is the product of the anaerobic (without air) decomposition of organic matter by bacteria. The natural gas we use today was formed by the decomposition of organic material millions of years ago. Hydrocarbons. such as methane are discussed in Chapter 4. 

Methane (METH-ane) is a colorless, odorless, tasteless, flammable gas that is less dense then air. It is the primary component of natural gas. Methane is the simplest of all hydrocarbons, organic compounds that contain carbon and hydrogen and no other elements. 

Film coefficients for turbulent flow that exist on the outside or shell side of the conventional baffled shell and tube exchanger are correlated for hydrocarbons, organic compounds, water, aqueous solutions, and gases by... 

Not all organic compounds that contain —OH groups are soluble in water (Table 10.1). As molar mass increases, the polar —OH group represents an increasingly smaller portion of the molecule. At the same time, the nonpolar hydrocarbon portion becomes larger. As a result, solubility decreases with increasing molar mass. Butanol, CH3CH2CH2CH2 OH, is... 

Haapakka and Kankare have studied this phenomenon and used it to determine various analytes that are active at the electrode surface [44-46], Some metal ions have been shown to catalyze ECL at oxide-covered aluminum electrodes during the reduction of hydrogen peroxide in particular. These include mercu-ry(I), mercury(II), copper(II), silver , and thallium , the latter determined to a detection limit of <10 10 M. The emission is enhanced by organic compounds that are themselves fluorescent or that form fluorescent chelates with the aluminum ion. Both salicylic acid and micelle solubilized polyaromatic hydrocarbons have been determined in this way to a limit of detection in the order of 10 8M. 

Unlike petroleum hydrocarbons, organic compounds in general followed a different evolutionary path. Chlorinated solvents are a common group of organic compounds, and are also the most frequently encountered contaminant in groundwater. Common industrial chemicals that are characterized as chlorinated solvents include trichloro-ethene (TCE), 1,1,1-trichloroethane (TCA), tetrachloroethene (PCE) or perchloro-ethylene, chlorofluorocarbon (Freon)-113 (i.e., 1,1,2-trichloroethane or 1,2,2-tri-fluoroethane), and methylene chloride. In 1997, the EPA reported the presence of TCE and PCE in 852 of 945 groundwater supply systems throughout the United States and in 771 of 1420 Superfund sites. 

Thus, transition metal cations in the lower valence state may also act as Lewis bases. Factors that affect the reactions promoted by Lewis acidity are listed in Table I. Lewis acid sites reversibly adsorb water (6s 9, 42), which may thus strongly compete with organic compounds that have weaker Lewis base properties, such as aromatic hydrocarbons. Lewis acidity depends on the degree of hydration and is strongest under desiccating conditions. Examples of reactions that are promoted by Lewis acidity are summarized in Table II. Other examples have been reviewed by Solomon and Howthorne (37). 

In this section, you reviewed how to name and draw alkanes, alkenes, and alkynes. You also learned how to name aromatic hydrocarbons. The names of all the other organic compounds you will encounter in this unit are based on the names of hydrocarbons. In the next section, you will learn about organic compounds that have single bonds to halogen atoms, oxygen atoms, and nitrogen atoms. 

When the carbonyl group occurs within a hydrocarbon chain, the compound is a ketone. A ketone is an organic compound that has a double-bonded oxygen on any carbon within the carbon chain. The functional group of a ketone is... 

The coupling of two mass spectrometer systems has received attention in recent years. This system can be operated in an atmospheric pressure mode by passing the air matrix directly into the ionization source (II). This method minimizes sample contamination and degradation problems. Detection limits are compound-dependent and can vary over more than an order of magnitude for different families of hydrocarbons. For example, an aromatic hydrocarbon such as toluene cannot be detected at levels below 5 ppbv, whereas most aldehydes are detectable at levels as low as 50 pptrv. The tandem MS-MS system has the potential to be a useful detection system for organic compounds that do not store well in collection containers. 

Another important class of organic compounds that we shall meet frequently, even in the early chapters of the text, are the carboxylic acids. These compounds are characterized by the carboxyl group, — COOH (7). As their names suggest, these compounds are acids. The most common example is acetic acid, CH3COOH (8 formally, ethanoic acid), the acid that gives vinegar its sharp taste. Another simple carboxylic acid is formic acid, HCOOH (9 formally, methanoic acid), the acid of ant venom. Note how the systematic (formal) names of the carboxylic acids are derived from the parent hydrocarbons (ethane and methane, respectively) by adding -anoic acid as a suffix to the stems eth- and meth-. 

Hydrocarbon An organic compound that contains hydrogen and carbon. 

Hydrocarbons Hydrocarbons are the simplest organic compounds that consist of only C and H atoms. Main sources of hydrocarbons are plants, bacteria, and internal combustion engines. Almost all usable supplies of hydrocarbons are obtained from combustion of coal, petroleum, and natural gas. 

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