Arenes trivial names

Many trivial names persist, particularly for aromatic, or arene alcohols (phenols) ... 

Substituted arenes are common and trivial names abound. Regrettably, replacement of trivial names for aromatic compounds by more systematic ones lags far behind nonaromatic systems. Thus, CgHsCHs is variously called methylbenzene or toluene, while its dimethyl isomers (Figure 5.1) are referred to as xylenes. 

In addition to the trivial names already mentioned, a number of more specific group names for arenes with side chains are also retained. 

What I had you do in the previous section probably seemed trivial. If so, that s good. It s common for us to specify a certain quantity of things with a special name, such as a dozen, gross, or bushel. If you had 30 pennies, you had 2.5 dozen pennies, 10 griks of pennies, and 3.75 fooms of pennies. There s a quantity often used in chemistry to specify how many atoms or molecules of a substance you have, and it s called a mole. One mole contains 6.02214 x 10 atoms or molecules, and this number is known as Arogadro s number. One mole of hydrogen molecules contains 6.02214 x 10 hydrogen molecules. One mole of xenon atoms contains 6.02214 x 10 xenon atoms. For that matter, one mole of pennies contains 6.02214 x 10 pennies, but there aren t that many pennies in existence. 

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