Alkanes Hydrocarbons containing only single properties

Alkane Hydrocarbon containing only single carbon-carbon bonds. The simplest example is methane, CK, 580 cis-trans isomer in, 598 isomers in, 580-582 nomenclature, 582t physical properties, 591t sources, 583-585 structural isomerism, 597 tests for, 602 uses, 583-585... 

Hydrocarbons contain only C and H atoms, so their physical properties depend on the strength of their dispersion forces. The names of organic compounds have a root for the longest chain, a prefix for any attached group, and a suffix for the type of compound. Alkanes (CnHan+a) have only single bonds. Cycloalkanes (C Hp ) have ring structures that are typically nonplanar. Alkenes (CnHpn) have at least one C=C bond. Alkynes (CnHpn-p) have at least one C=C bond. Aromatic hydrocarbons have at least one planar ring with delocalized tt electrons. 

We begin our study with hydrocarbons, which have the general empirical formula QHj,. Those containing only single bonds, such as methane, ethane, and propane, are called alkanes. Molecules such as cyclohexane, whose carbons form a ring, are called cycloalkanes. Alkanes lack functional groups as a result, they are relatively nonpolar and unreactive. The properties and chemistry of the alkanes are described in this chapter and in Chapters 3 and 4. 

Alkane properties Alkanes are nonpolar compounds with relatively low melting and boiling points compared to polar molecules of similar mass. Alkanes have low solubilities in water. They also have low reactivities, but they readily undergo combustion in oxygen and are commonly used as fuels. Alkanes are saturated hydrocarbons that contain only single bonds. In the next section, you will examine unsaturated hydrocarbons, which have at least one double or triple bond between carbon atoms. 

Most of the hydrocarbons in crude oil belong to the family of compounds called alkanes. The molecules within the alkane family contain carbon atoms covalendy bonded to four other atoms by single bonds (Figure 14.2). Because these molecules possess only single bonds they are said to be saturated, as no further atoms can be added. This can be seen in the bonding scheme for methane (Figure 14.3). The physical properties of the first six members of the alkane family are shown in Table 14.1. 

Alkanes are saturated hydrocarbons that is, they contain only carbon-carbon single bonds. In this context, "saturated" means that each carbon has the maximum number of hydrogens bonded to it. We often refer to alkanes as aliphatic hydrocarbons, because the physical properties of the higher members of this class resemble those of the long carbon-chain molecules we find in animal fats and plant oils (Greek aleiphar, fat or oil). 

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