The most characteristic reactions of benzenoid arenes are the substitution reactions that occur when they react with electrophilic reagents. The electrophiles are either a positive ion (E+) or some other electron-deficient species with a large partial positive charge

More reactive than benzene toward electrophilic substitution NO2 An deactivating group Less reactive than benzene toward electrophilic substitution Ortho-para director Meta director

Phenols are like alcohols in being able to form strong intermolecular hydrogen bonds. Phenols have higher boiling points than hydrocarbons of the same molecular weight. A modest solubility in water

Carbon’s ability to form strong covalent bonds to other carbon atoms is the single property of the carbon atom that — more than any other—accounts for the existence of a field of study called organic chemistry. Carbon’s ability to form as many as four strong bonds to other carbon atoms, and to form strong bonds to hydrogen, oxygen, sulfur, and nitrogen atoms as well

An acid is a substance that can donate (or lose) a proton, A base is a substance that can accept (or remove) a proton

Energy and the Relative Stability Kinetic energy is the energy an object has because of its motion. Potential energy is stored energy. It exists only when an attractive or repulsive force exists between objects

The primary source of alkanes is petroleum Natural gas consists chiefly of methane, but ethane, propane, butane, and isobutane are also present. Petroleum is a complex mixture of hydrocarbons that must be refined into different fraction before it can be used

The C—X bond of alkyl halides is polarized. The carbon atom bears a partial positive charge, The halogen atom a partial negative charge

First order overall (一级反应) The reaction is a unimolecular nucleophilic substitution（单分子亲核取代反应）

1. The experimental conditions — temperature and acid concentration — that are required to being about dehydration are closely related to the structure of the individual alcohol. The relative ease with which alcohols undergo dehydration is in the following order: