Alkanes Are Unreactive Compounds

We have seen that the carbon-carbon double and triple bonds of alkenes and alkynes are composed of strong a bonds and weaker tt bonds and that, because of their relatively weak tt bonds, alkenes and alkynes undergo electrophilic addition reactions (Sections 6.0 and 7.5). 

Alkanes have only strong a bonds. In addition, the electrons in the C—C and C—H cr bonds are shared equally by the bonding atoms, so none of the atoms in an alkane has any significant charge. This means that alkanes are neither nucleophiles nor electrophiles, so neither electrophiles nor nucleophiles are attracted to them. Alkanes, therefore, are relatively unreactive compounds. The failure of alkanes to undergo reactions prompted early organic chemists to call them paraffins, from the Latin parum affiinis, which means little affinity (for other compounds). 

Natural gas is approximately 75% methane. The remaining 25% is composed of other small alkanes such as ethane, propane, and hutane. In the 1950s, natural gas replaced coal as the main energy source for domestic and industrial heating in many parts of the United States. 

Modem society faces three major problems as a consequence of our dependence on fossil fuels for energy. First, these fuels are a nonrenewable resource and the world s supply is continually decreasing. 

Second, a group of Middle Eastern and South American countries controls a large portion of the world s supply of petroleum. These countries have formed a cartel called the Organization of Petroleum Exporting Countries (OPEC) that controls both the supply and the price of cmde oil. Political instability in any OPEC country can seriously affect the world s oil supply. 

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