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olefines's Usage Examples:

The olefines may be synthetically prepared by eliminating water from the alcohols of the general formula CnH2n+1 OH, using sulphuric acid or zinc chloride generally as the dehydrating agent, although phosphorus pentoxide, syrupy phosphoric acid and anhydrous oxalic acid may frequently be substituted.

The higher olefines are found in the tar which is obtained by distilling bituminous shales, in illuminating gas, and among the products formed by distilling paraffin under pressure (T.

The simple olefines containing one doublylinked pair of carbon atoms have the general formula (CnH2n; the di-olefines, containing two doubly-linked pairs, have the general formula C0H2n_2 and are consequently isomeric with the simple acetylenes.

The same difference attends the introduction of the methyl group into many classes of compounds, for example, the paraffins, olefines, acetylenes, aromatic hydrocarbons, alcohols, aldehydes, ketones and esters, while a slightly lower value (157.1) is found in the case of the halogen compounds, nitriles, amines, acids, ethers, sulphides and nitro compounds.

For example: nitric acid and sulphuric acid readily react with benzene and its homologues with the production of nitro derivatives and sulphonic acids, while in the aliphatic series these acids exert no substituting action (in the case of the olefines, the latter acid forms an addition product); another distinction is that the benzene complex is more stable towards oxidizing agents.

The product actually obtained is a mixture of several paraffins and several olefines.

In an experiment on 3500 grams of paraffin produced from shale (melting point 44'5° C.) they obtained nearly 4 litres of liquid hydrocarbons, which they subjected to fractional distillation, and on examining the fraction distilling below loo° C., they found it to consist mainly of olefines.

Paraffins are found in all crude oils, and olefines in varying proportions in the majority, while acetylene has been found in Baku oil; members of the benzene group and its derivatives, notably benzene and toluene, occur in all petroleums. Naphthenes are the chief components of some oils, as already indicated, and occur in varying quantities in many others.

The principal elements are found in various combinations, the hydrocarbons of the Pennsylvania oils being mainly paraffins (q.v.), while those of Caucasian petroleum belong for the most part to the naphthenes, isomeric with the olefines (q.v.).

ethylene dibromide) with silver acetate or with potassium acetate and alcohol, the esters so produced being then hydrolysed with caustic alkalis, thus: C 2 H 4 Br 2 + C2H302 Ag-*C2H4(O C2H30)2->C2H4(OH)2+2K C2H302 by the direct union of water with the alkylen oxides; by oxidation of the olefines with cold potassium permanganate solution (G.

olefines's Meaning':

any unsaturated aliphatic hydrocarbon