ABSTRACT
Environmental regulations list hundreds of chemical pollutants. Almost all are organic and toxic. The US Environmental Protection Agency (EPA) Clean Water Act lists 148 pollutants. One broad class of organic compounds is the aliphatics. Their basic structure is a carbon chain. The other broad class is the aromatics. They have ring structures, mostly of six carbon atoms. The structure of the alkanes is very simple. Each carbon atom has four bonding sites. Carbons bond to carbons, and hydrogen atoms fill up the remaining bonds. Methane has one carbon atom, and all four bonding sites are filled with hydrogen atoms. Removing one hydrogen atom from an alkane creates a functional group. The next most simple structure is the alkenes. Alkenes are alkanes with at least one carbon-carbon double bond. Aromatic organic compounds are so named because many of them have distinct aromas or fragrances.
