464 



CONSIDERATION OF CARBON COMPOUNDS. 



First member. 

 CH 4 

 C 2 H 4 

 C 2 H 2 



In regard to chemical properties, it may be said that hydrocarbons 

 are neutral substances, behaving rather indifferently toward most 

 other chemical agents. Many of them are, however, oxidized by the 

 oxygen of the air, by which process liquid hydrocarbons are often 

 converted into solids. The action of halogens on hydrocarbons will 

 be considered later on. 



A number of homologous series of hydrocarbons are known, of 

 which the following are the most important : 



General formula. 



Methane series or paraffins, C n H2 U + 2 



Ethene series or olefins, C n H 2n 



Eihine series or acetylenes, C n H 2n _ 2 



Terpenes, C n H 2n _ 4 C 10 H 16 



Benzene series, C n H 2n - e C 6 He 



Of the acetylene series and of the terpenes only a few homologues 

 are known. 



The univalent radicals of the members of the methane series are designated 

 by changing the termination ane to yl (methane, methyl, CH 3 ! ) ; the bivalent 

 radicals by changing ane to ene (rnethene, CH 2 ]i ) ; and the trivalent radicals 

 by changing the final e of ene to yl (methenyl, CH U1 ). The derivatives of the 

 bivalent radicals are indicated by the termination ylene, as methylene iodide, 

 CH 2 I 2 . 



i 



Hydrocarbons of the paraffin or methane series. The hydro- 

 carbons having the general composition C n H 2n + 2 are known as 

 paraffins, the name being derived from the higher members of the 

 series which form the paraffin of commerce. The following table 

 gives the composition, boiling-points, etc., of the first sixteen mem- 

 bers of this series : 



Methane or methyl hydride, 

 Ethane or ethyl hydride, 

 Propane or propyl hydride, 

 Butane or butyl hydride, 

 Pentane or amyl hydride, 

 Hexane or hexyl hydride, 

 Heptane or heptyl hydride, 

 Octane or octyl hydride, 

 Nonane or nonyl hydride, 

 Decane or decyl hydride, 

 Undecane or undecyl hydride, 

 Dodecane or dodecyl hydride, 

 Tridecane or tridecyl hydride, 

 Tetradecane or tetradecyl hydride, 

 Pentadecane or pentadecyl hydride, 

 Hexadecane or hexadecyl hydride, 

 etc. 



B. P. 



Sp. gr. 



H 



H 



H 



