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Home >> Chemistry Dictionary >>Ethene (ethylene) - Ethylation
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Ethanoyl chloride.
(acetyl chloride) A colourless liquid acyl chloride (see acyl halides), CH3COCI, with a pungent smell; r.d. 1.104; m.p. – 112.15°C; b.p. 55°C. It is made by reacting ethanoic acid with a halogenating agent such as phosphorus (III) chloride, phosphorus (V) chloride, or sulphur dichloride oxide and is used to introduce ethanoyl groups into organic compounds containing – OH, - NH2, and – SH groups.
Ethanoyl group.
(acetyl group) The organic group CH3CO-.
Ethene (Ethylene).
A colourless flammable gaseous hydrocarbon, C2H4; m.p. 169°C; b.p. - 102°C. It is the first member of the alkene series of hydrocarbons. It is made by craking hydrocarbons from petroleum and is now major raw material for making other organic chemical e.g. ethanal, ethanol, ethane – 1, 2 – diol. It can be polymerized to polyethene. It occurs naturally in plants in which it acts as a growth substance promoting the ripening of fruits.
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It is given off in minute amounts by the ripe tomatoes and apples and has the property of accelerating the ripening of fruit. Also used in the manufacture of glycol. (20%), ethylene oxide (15%), ethanol, styrene (14%), dichloroethane, ethyl chloride, vinyl ester,s e.g. vinyl ethanoate and vinyl ethers, vinyl chloride (10%). When polymerized under high pressure, or at lower pressures in the presence of a catalyst, it gives the important plastic polyethylene (40%).
Ethers.
Organic compounds containing the group – O – in their molecules. Examples are dimethyl ether, CH3OCH3, and diethyl ether, C2H5OC2H5 (see ethoxyethane). They are volatile highly flammable compounds made by dehydrathing alcohols using sulphuric acid.
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Ethoxyethane.
(Diethyl ether; ether) A colourless flammable volatile ether. C2H5OC2H5; r.d. 0.71; m.p. - 116°C; b.p. 34.5°C. It can be made by Williamson’s synthesis. It is an anaesthetic and useful organic solvent.
Ethyl Acetate.
Ethyl ester of acetic acid, CH3COOC2H5, a colourless volatile liquid.
Ethyl Carbamate.
[Urethan(e). NH2COOC2H5]. A white crystalline solid, m.p. 48°C. Used in the molten state as a solvent. It is used as an intermediate in the manufacture of resins and in medicine.
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Ethoxy.
The CH3CH2O – group; EtO - .
Ethoxyl.
The group CH3CH2O - ; also written EtO - .
Ethyl.
The group CH3.CH2 - ; oftenwritten C2H5 – and Et - .
Ethylation.
Processes by which an ethyl group is added to a compound. In aliphatic chemistry this involves the substitution of the hydrogen atom of a hydroxyl, amino or imino group, and produces an ether or a secondary or tertiary amine respectively. In aromatic chemistry it may also mean the substitution of one of the hydrogen atoms of the ring by the ethyl group; this is carried out by the Friedel-Crafts reaction.
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Ethylene Oxide.
1, 2 – epoxyethane, oxirane CH2.CH2O. Colourless gas with a sweet odour which is somewhat lachrymatory; b.p. 10.5°C. Manufactured by heating ethylene chlorohydrin with Ca(OH)2 or NaOH solution; or by the direct oxidation of ethane at 250 - 230°C using a silvery catalyst. It forms an explosive mixture with air. Reacts with water in the presence of sulphuric acid to give ethylene glycol and polyethylene glycols; with alcohols and phenols to give ethers of glycol; and with hydrochloric acid to give ethylene chlorohydrin. It reacts with many primary and secondary amines to give ethanolamines; with organic acids to give monoesters of ethylene glycol, and with acid anhydrides to give diesters. It is reduced by hydrogen to ethanol, and is converted to ethanal by heating at 200 - 300°C in the presence of alumina. Its principal use is for polymerization to 1, 2 – epoxide polymers. It is also used as an intermediate in the manufacture of ethylene glycol, polyethylene glycols, glycol ethers, ehtanolamines and similar compounds.
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Ethyl ethanoate.
Ethyl acetate, acetic ester, acetic ether, CH3CO2 C2H5. Colourless liquid; b.p. 77°C, with a pleasant fruity odour. Manufactured from ethanol, ethanoic acid and concentrated sulphuric acid, or from Ethyne via ethanal with an aluminium alkoxide as catalyst. It is an extremely useful solvent, expecially for cellulose – type varnishes and adhesives; also used for cosmetic applications and as an artificial essence.
Ethyl fluid.
See anti – knock additives.
Ethyl formate.
See ethyl methanoate.
Ethyl hydrogen sulphate.
Ethylsulphuric acid. C2H6O4S, (EtO) (HO) SO2. Any oil liquid. Soluble in water sour in taste and having acid reaction.
Ethyl nitrate.
(C2H5ONO2). A colourless pleasant – smelling liquid (b.p. 633.5 k). It is immiscible with water. It is heavier than water. When reduced with tin and hydrochloric acid, it gives ethanol and hydroxyl amine.
C2H5ONO2 + 6 (H) ® C2H5OH + NH2OH + H2O
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