ORGANIC MOLECULES ARE CLASSIFIED BY FUNCTIONAL GROUP

A hydrocarbon structure can serve as a framework to which various heteroatoms can be attached. This is analogous to a Christmas tree serving as the scaffolding on which ornaments are hung. Just as the ornaments give character 

Organic molecules are classified according to the functional groups they contain, where a functional group is defined as a combination of atoms that behave as a unit. Most functional groups are distinguished by the heteroatoms they contain, and some common groups are listed in Table 12.1. 

Was this your answer Heteroatoms largely determine an organic molecule s personality.  

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Because lowering the surface tension is the most important physical property of a defoamer, it is reasonable to classify the defoamer by the hydrophobic operation of the molecule. In contrast, the classification of organic molecules by functional groups are often polar and hydrophilic (i.e., alcohol, acid, and salt are common in basic organic chemistry). Four classes of defoamers are known as liquid phase components ... 

It may seem strange to classify a type of bond as a functional group, but you will see later that C=C double bonds impart reactivity to an organic molecule just as functional groups consisting of, say, oxygen or nitrogen atoms do. Some of the compounds produced by plants and used by perfumers are alkenes (see Chapter 1). For example, pinene has a smell evocative of pine forests, while limonene smells of citrus fruits. 

Because the longest chain consists of three carbon atoms, the name for this compound is based on propane. From Table i, you can see that the presence of the —OH functional group classifies this compound as an alcohol. Therefore, as indicated by Table 4, the name for this compound is propanol, whose suffix -ol indicates that this molecule is an alcohol. Because the functional group is attached to the second carbon atom, the correct name for this compound is 2-propanol. A number of organic compounds are often referred to by their common names, even by chemists. The common name for 2-propanol is isopropyl alcohol. 

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