is employed for dissolving ionic compounds when water cannot be used.
ethanoate (acetate) A salt or ester
of ethanoic acid (acetic acid).
ethanoic acid (acetic acid) A clear
viscous liquid or glassy solid *carboxylic acid, CH 3 COOH, with a characteristically sharp odour of vinegar;
r.d. 1.049; m.p. 16.6°C; b.p. 117.9°C.
The pure compound is called glacial
ethanoic acid. It is manufactured by
the oxidation of ethanol or by the oxidation of butane in the presence of
dissolved manganese(II) or cobalt(II)
ethanoates at 200°C, and is used in
making ethanoic anhydride for producing cellulose ethanoates. It is also
used in making ethenyl ethanoate
(for polyvinylacetate). The compound
is formed by the fermentation of alcohol and is present in vinegar,
which is made by fermenting beer or
wine. ‘Vinegar’ made from ethanoic
acid with added colouring matter is
called ‘nonbrewed condiment’. In living organisms it combines with *coenzyme A to form acetyl coenzyme
A, which plays a crucial role in energy metabolism.
ethanoic anhydride (acetic anhydride) A pungent-smelling colourless
liquid, (CH 3 CO) 2 O, b.p. 139.5°C. It is
used in organic synthesis as an
*ethanoylating agent (attacking an
–OH or –NH group) and in the manufacture of aspirin and cellulose plastics. It hydrolyses in water to give
ethanoic acid.
ethanol (ethyl alcohol) A colourless
water-soluble *alcohol, C 2 H 5 OH; r.d.
0.789 (0°C); m.p. –117.3°C; b.p.
–78.3°C. It is the active principle in
intoxicating drinks, in which it is
produced by fermentation of sugar
using yeast
C 6 H 12 O 6 → 2C 2 H 5 OH + 2CO 2
The ethanol produced kills the yeast
and fermentation alone cannot produce ethanol solutions containing
more than 15% ethanol by volume.
Distillation can produce a constantboiling mixture containing 95.6%
ethanol and 4.4% water. Pure ethanol
(absolute alcohol) is made by removing this water by means of drying
agents.
The main industrial use of ethanol
is as a solvent although at one time it
was a major starting point for making other chemicals. For this it was
produced by fermentation of molasses. Now ethene has replaced
ethanol as a raw material and industrial ethanol is made by hydrolysis of
ethene.
ethanolamine Any of three lowmelting hygroscopic colourless
solids. They are strong bases, smell of
ammonia, and absorb water readily
to form viscous liquids. Monoethanolamine, HOCH 2 CH 2 NH 2 , is a
primary *amine, m.p. 10.5°C; diethanolamine, (HOCH 2 CH 2 ) 2 NH, is a
secondary amine, m.p. 28°C; and triethanolamine, (HOCH 2 CH 2 ) 3 N, is a
tertiary amine, m.p. 21°C. All are
made by heating ethylene oxide with
concentrated aqueous ammonia
under pressure and separating the
products by fractional distillation.
With fatty acids they form neutral
soaps, used as emulsifying agents
and detergents, and in bactericides
and cosmetics.
ethanoylating agent (acetylating
agent) A chemical reagent used to
introduce an ethanoyl group
(–COCH 3 ) instead of hydrogen in an
organic compound. Examples include
*ethanoic anhydride and ethanoyl
chloride (acetyl chloride, CH 3 COCl).
ethanoyl chloride (acetyl chloride)
A colourless liquid acyl chloride (see
acyl halides), CH 3 COCl, with a pungent smell; r.d. 1.105; m.p. –112.15°C;
b.p. 50.9°C. It is made by reacting
ethanoic acid with a halogenating
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ethanoyl chloride
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ethanoate (acetate) A salt or ester
of ethanoic acid (acetic acid).
ethanoic acid (acetic acid) A clear
viscous liquid or glassy solid *carboxylic acid, CH 3 COOH, with a characteristically sharp odour of vinegar;
r.d. 1.049; m.p. 16.6°C; b.p. 117.9°C.
The pure compound is called glacial
ethanoic acid. It is manufactured by
the oxidation of ethanol or by the oxidation of butane in the presence of
dissolved manganese(II) or cobalt(II)
ethanoates at 200°C, and is used in
making ethanoic anhydride for producing cellulose ethanoates. It is also
used in making ethenyl ethanoate
(for polyvinylacetate). The compound
is formed by the fermentation of alcohol and is present in vinegar,
which is made by fermenting beer or
wine. ‘Vinegar’ made from ethanoic
acid with added colouring matter is
called ‘nonbrewed condiment’. In living organisms it combines with *coenzyme A to form acetyl coenzyme
A, which plays a crucial role in energy metabolism.
ethanoic anhydride (acetic anhydride) A pungent-smelling colourless
liquid, (CH 3 CO) 2 O, b.p. 139.5°C. It is
used in organic synthesis as an
*ethanoylating agent (attacking an
–OH or –NH group) and in the manufacture of aspirin and cellulose plastics. It hydrolyses in water to give
ethanoic acid.
ethanol (ethyl alcohol) A colourless
water-soluble *alcohol, C 2 H 5 OH; r.d.
0.789 (0°C); m.p. –117.3°C; b.p.
–78.3°C. It is the active principle in
intoxicating drinks, in which it is
produced by fermentation of sugar
using yeast
C 6 H 12 O 6 → 2C 2 H 5 OH + 2CO 2
The ethanol produced kills the yeast
and fermentation alone cannot produce ethanol solutions containing
more than 15% ethanol by volume.
Distillation can produce a constantboiling mixture containing 95.6%
ethanol and 4.4% water. Pure ethanol
(absolute alcohol) is made by removing this water by means of drying
agents.
The main industrial use of ethanol
is as a solvent although at one time it
was a major starting point for making other chemicals. For this it was
produced by fermentation of molasses. Now ethene has replaced
ethanol as a raw material and industrial ethanol is made by hydrolysis of
ethene.
ethanolamine Any of three lowmelting hygroscopic colourless
solids. They are strong bases, smell of
ammonia, and absorb water readily
to form viscous liquids. Monoethanolamine, HOCH 2 CH 2 NH 2 , is a
primary *amine, m.p. 10.5°C; diethanolamine, (HOCH 2 CH 2 ) 2 NH, is a
secondary amine, m.p. 28°C; and triethanolamine, (HOCH 2 CH 2 ) 3 N, is a
tertiary amine, m.p. 21°C. All are
made by heating ethylene oxide with
concentrated aqueous ammonia
under pressure and separating the
products by fractional distillation.
With fatty acids they form neutral
soaps, used as emulsifying agents
and detergents, and in bactericides
and cosmetics.
ethanoylating agent (acetylating
agent) A chemical reagent used to
introduce an ethanoyl group
(–COCH 3 ) instead of hydrogen in an
organic compound. Examples include
*ethanoic anhydride and ethanoyl
chloride (acetyl chloride, CH 3 COCl).
ethanoyl chloride (acetyl chloride)
A colourless liquid acyl chloride (see
acyl halides), CH 3 COCl, with a pungent smell; r.d. 1.105; m.p. –112.15°C;
b.p. 50.9°C. It is made by reacting
ethanoic acid with a halogenating
213
ethanoyl chloride
e
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