In the addition of HX to an unsymmetrically substituted alkene, the hydrogen atom adds to the carbon atom of the double bond that already has the greater number of hydrogen atoms and that the X group adds to the carbon having more alkyl substituents. Markovnikov’s rule can be restated by saying that, in the addition of HX to an alkene, the more stable carbocation intermediate is formed

There is a group of compounds in which carbon forms only two bonds. These neutral divalent carbon compounds are called carbenes. Most carbenes are highly unstable compounds that are capable of only fleeting existence. Soon after carbenes are formed they usually react with another molecule

These spectra are often called carbon magnetic resonance (CMR) spectra or 13C NMR spectra. In some important ways 13C spectra are usually les complex and easier to interpret than proton (1H) NMR spectra

A mass spectrometer produces a spectrum of masses based on the structure of a molecule. It is a spectrum or plot of the distribution of ion masses corresponding to the formula weight of a molecule, fragments derived from the molecule, or both

How are molecular structures determined? One way is though the use of spectroscopic methods. Spectroscopy is the study of the interaction of energy with matter. When energy is applied to matter it can be absorbed, emitted, cause a chemical change, or be transmitted

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:

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

Isomers are different compounds that have the same molecular formula. Constitutional isomers are isomers that differ because their atoms are connected in a different order. Stereoisomers differ only in arrangement of their atoms in space.Stereoisomers are not constitutional isomers. Enantiomers are stereoisomers whose molecules are nonsuperposable mirror images of each other. Diastereomer are stereoisomers whose molecules are not mirror images of each other

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

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