Page:Encyclopædia Britannica, Ninth Edition, v. 5.djvu/570

Rh 558 CHEMISTRY [ORGANIC. ISOPARAFFINS. Names. Formulae. Boiling- points. Specific gravities. { CH, Isotetrane or trimethyl-me- HC I CH 3 -15 C. thane. (CH S Isopentane or ethyl-dime- j thyl-methane ) HC C 2 H S CH. ntr 30 1 f Propyl-dimethyl- ( C 3 H 7 HC { CH 3 62 701 at C. Isohex- methane ( CH 3 anes Diethyl-methyl- j i. methane 1 ) HC J C H* (CH 3 ?

Tetryl-dimethyl- &quot;&amp;gt; methane ) HC C 4 H 9 CH 3 CH, 90 683 at 18 Isohept- j anes Trie thyl-methane. . . HC C 2 H 5 96 689 at 57 Propyl-ethyl-me- w thyl-methane 1 ....

HC C 3 H 7 C 2 H 5 CH/

Isooctane thyl-m or pentyl-dime- j ethane ) HC CH 3 CH 3 124? 708 at 12 5 - These compounds have not hitherto been obtained, hut are intro duced in order to illustrate how the &quot; constitution &quot; theory of isoiner- ism enables the existence of new compounds to be predicted with considerable certainty. NEOPARAFFINS. Names. Formulae. Boiling- points. Specific gravity. CH 3 Neopentane or tetramethyl- ) methane C CH 3 CH 3 9 5C. ? CH 3 Neohexan* ethyl-m ethane j C CH 3 5 CH 3 43-48
 * or trimethyl- )

Utl 3 Trimethyl-pro- ) pyl-methane 2 C CH 3 CH 3 CH!

Neohept- _ anes C 2 H 5 Diethyl-dime- ) . thyl-methane ) C CH/ 86-87 696 at 20-5 CH 3 MESOPARAFFINS. Names. Formulae. Boiling- points. Specific gravities. Meso-hexane or tetrame thyl-ethane ( HC(CH 3 ) 2 j HC(CH 3 ) 2 59 C. 670 at 17 rHC(CH 3 ) 2 Meso-octane or tetrame- (CH 2 ) 2 110 698 at 16 lHC(CH 3 ) 2 rHC(CH 3 ) 2 Meso-nonane or tetrame- thyl-pentane 132 724 at O u LHC(CH 3 ) 2 fHC(CH 3 ) 2 Meso-deeane or tetrame- thyl-hexane 158 727 at 14 lHC(CH 3 ) 2 We now proceed to give a few methods of preparing some of the more important paraffins, which methods do not come under the previously described general processes of formation. Methane. This hydrocarbon is found as a constituent of coal-gas where it is produced by the destructive dis tillation of coal. It is formed synthetically by passing a mixture of carbon disulphide vapour and steam (or sul phuretted hydrogen) over copper heated to redness in a tube : CS 2 + 2SH 2 + 4Cu = CH 4 + 4CuS . Tetrane may be prepared by exposing ethyl iodide over mercury to the action of sunlight : Isopentane (ethyl-dimethyl-methane) is formed by the dehydration of amyl alcohol by means of zinc chloride. Neopentane (tetramethyl-methane) is prepared by the action of zinc-methide on trimethyl-iodomethane(katabutyl- iodide) : 2C(CH 3 )I + Zn(CH 3 ) 2 = ZnI 2 + 2C(CH 3 ) 4 . Hexane is produced by the action of hydriodic acid on benzene at 280 : Meso-hexane (tetramethyl-ethane) is formed by the action of hydriodic acid on pinacone a substance having the formula HOC(CH 3 ) 2 HOC(CH 3 ) 2 produced by the action of sodium amalgam on dimethyl ketone in presence of water. Isoheptane (tetryl-dimethyl-methane) is produced by the action of sodium on a mixture of the bromides of ethyl and amyl. Solid Paraffin is, when purified, a white wax-like sub stance, melting between 40 and 60, and boiling about 370. It is contained in the tar produced by the distilla tion of Boghead and cannel coals, and is probably a mixture of several of the higher members of the C.H 2B+2 series. Second Series, C M H 2 . Olefine 1 Series. General Properties. These hydrocarbons furnish a good illustration of polymerism, as they form a series which is both homologous and polymeric. Being unsaturated com pounds, they act as dyad radicles, uniting with C1 2, Br 2 , O, HC1, HBr, HI, C1HO, &c. The haloid compounds of the olefines treated with alcoholic potash give up one halogen atom and furnish mono-haloid derivatives : C n ~R. 2n Ha. 2 + KHO - CJl^i 11 &quot; + ^ Ha + OH 2 These mono-haloid olefines can again combine with 7/a 2 and again lose Ha by the action of KHO : Di-haloid olefine. In this way 3,4 n atoms of hydrogen can be replaced by Ha y Ha 4, Ha n atoms of halogen, and the final product can again unite with Ha 2, forming a per-haloid paraffin deriva tive. For instance : Cm _L r&amp;lt;i - r* Pi 2^4 ^2 &quot; &quot; ^&quot;26 * Tetrachlorethene. &quot; Hexachlorethane. The compounds of olefines with hypochlorous acid yield the corresponding alcohols by the action of nascent hydrogen : C n H 2n ClHO + H 2 = C n H 2n+1 .OH + HC1. 1 So called from the oily liquids which these hydrocarbons produce when combined with chlorine.
 * See note to last table.
 * (CH 2 ) 3
 * (CH 2 ) 4