Ethyl acetate

From New World Encyclopedia
Revision as of 18:10, 22 September 2007 by Dinshaw Dadachanji (talk | contribs) (imported latest version of article from Wikipedia)
(diff) ← Older revision | Latest revision (diff) | Newer revision → (diff)
Ethyl acetate
Ethyl acetateEthyl acetate
General
IUPAC name Ethyl acetate
Systematic name Ethyl ethanoate
Other names ethyl ester,
ethyl acetate,
acetic ester,
ester of ethanol
Molecular formula C4H8O2
SMILES CCOC(C)=O
Molar mass 88.105 g/mol
Appearance colorless liquid
CAS number [141-78-6]
Properties
Density and phase 0.897 g/cm³, liquid
Solubility in water 8.3 g/100 mL (20 °C)
Solubility in ethanol,
acetone, diethyl ether,
benzene
Miscible
Melting point −83.6 °C (189.55 K)
Boiling point 77.1 °C (350.25 K)
Critical temperature 250.11 °C (523.26 K)
Viscosity 0.426 cP at 25 °C
Structure
Dipole moment 1.78 D
Hazards
MSDS External MSDS
Main hazards Flammable (F),
Irritant (Xi)
NFPA 704

NFPA 704.svg

3
1
0
 
R-phrases R11, R36, R66, R67
S-phrases S16, S26, S33
Flash point −4 °C
RTECS number AH5425000
Supplementary data page
Structure and
properties
n = 1.3720
Thermodynamic
data
Phase behaviour
Solid, liquid, gas
Spectral data UV, IR, NMR, MS
Related compounds
Related carboxylate esters Methyl acetate,
Butyl acetate
Related compounds Acetic acid,
ethanol
Except where noted otherwise, data are given for
materials in their standard state (at 25 °C, 100 kPa)
Infobox disclaimer and references

Ethyl acetate is the organic compound with the formula CH3CH2OC(O)CH3. This colorless liquid has a characteristic, not unpleasant smell (similar to pear drops) like certain glues or nail polish removers , in which it is used. As the ester derived from ethanol and acetic acid, EtOAc, as it is commonly abbreviated, is manufactured on a large scale for use as a solvent.

Properties

Ethyl acetate is a moderately polar solvent that has the advantages of being volatile, relatively non-toxic, and non-hygroscopic. It is a weak hydrogen bond acceptor, and is not a donor due to the lack of an acidic proton (one directly bonded to an electronegative atom such as fluorine, oxygen, or nitrogen). Ethyl acetate can dissolve up to 3% water and has a solubility of 8% in water at room temperature. At elevated temperature its solubility in water is higher. It is unstable in the presence of strong aqueous bases and acids.

Uses and occurrence

Ethyl acetate is widely employed as a solvent for nail varnishes and nail varnish removers. Industrially it is used to decaffeinate coffee beans and tea leaves.[citation needed] In chemistry, it is often mixed with a non-polar solvent such as hexanes as a chromatography solvent. It is also used as a solvent for extractions. It is rarely used as a reaction mixture due to the weakness of the ester linkage — it hydrolyzes in the presence of strong acids and bases to give acetic acid and ethanol.

Ethyl acetate is also present in confectionery, perfumes, and fruits. It is used in perfumes because it evaporates at a fast rate, leaving but the scent of the perfume on the skin. It also confers a fruity smell, as do most esters. It is also used in paints as an activator or hardener.

Occurrence in wines

Ethyl acetate is present in wines. It may be considered a contaminant at too high concentrations, as typically occurs when wine is exposed to air for a prolonged period. When present at too high concentration in wine, it is regarded as an off-flavour.

Other uses

In the field of entomology, ethyl acetate is an effective poison for use in insect collecting and study. In a killing jar charged with ethyl acetate, the vapors will kill the collected (usually adult) insect quickly without destroying it. Because it is not hygroscopic, ethyl acetate also keeps the insect soft enough to allow proper mounting suitable for a collection.

Synthesis

Ethyl acetate is synthesized via the Fischer esterification reaction from acetic acid and ethanol, typically in the presence of an acid catalyst such as sulfuric acid.

CH3CH2OH + CH3COOH → CH3COOCH2CH3 + H2O

Because the reaction is reversible and produces an equilibrium, the yield is low unless water is removed. In the laboratory, the ethyl acetate product can be isolated from water using a Dean-Stark apparatus.

Reactions

Ethyl acetate can be hydrolyzed in acid or basic conditions to regain acetic acid and ethanol. The use of an acid catalyst such as sulfuric acid gives poor yields due to it being an equilibrium — the reverse reaction of the Fischer esterification.

To obtain high yields, it is preferable to use a stoichiometric amount of strong base, such as sodium hydroxide. This reaction gives ethanol and sodium acetate, which is not able to react with ethanol any longer:

CH3CO2C2H5 + NaOH → C2H5OH + CH3CO2Na

See also

External links

de:Ethylacetat es:Etanoato de etilo fr:Acétate d'éthyle id:Etil asetat it:Acetato di etile nl:Ethylacetaat ja:酢酸エチル pl:Octan etylu pt:Acetato de etila ru:Этилацетат fi:Etyyliasetaatti sv:Etylacetat vi:Axetat etyl zh:乙酸乙酯