Olefin refers to a hydrocarbon compound containing C = C (carbon-carbon double bond). Olefin is an unsaturated hydrocarbon, divided into chain olefin and cyclopyfin. The number of double bonds is called mono olefin, dizide, etc., respectively. The single-chain olefin molecular formula is CNH2N, and the C2-C4 is a gas at normal temperature. A double-key group is a functional group in olefin molecules. It has response activity. It can occur in hydrogenation, halogenization, hydrogenation, hydrogenation, hydatate, sulfate, and polymerization.
The physical properties of olefin can be compared with alkane. The physical state determines molecular quality. At the same temperature or normal temperature, in simple olefin, ethylene, acrylin, and butth clone are gas, liner olefins containing 5 to 18 carbon atoms are liquid, and more advanced olefins are wax solids.
At normal temperature, C2 ~ C4 olefin is gas; C5 ~ C18 is a volatile liquid; solids above C19. In the positive olefin, the boiling point increases with the increase of relative molecular quality. The boiling point of the same carbon number of positive olefin is higher than the olefin boiling point with a chain. In the olefin with the same carbon rack, the double bonds move from the chain end to the middle of the chain, and the boiling point, and the melting point increase.
The boiling point of transfer olefin is lower than the boiling point of a cashmereyfin, and the melting point is high, which is due to the transaction heterogeneous. Small polarity and good symmetry. Compared with the corresponding alkanes, the boiling point, refractive index, dissolving degree in water, and relative density are slightly smaller. Its density is smaller than water.
The chemical properties of olefins are relatively stable, but they are lively as an alkane. Considering that the carbon-carbon dual-bonding of carbon-carbon-carbon single bonds in olefin is strong, most of the response of the olefin has a double bond disconnect and forms two new single keys. The characteristic reactions of olefins occur in the functional group C = C and C-H.