Description of experiment
Below follows a plain text transcript of the selected experiment.
Needed compounds:
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2-propanol : CH3CHOHCH3
methanol : CH3OH
acetyl chloride : CH3COCl
Class:
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elem=C,Cl
organic
Summary:
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Acetyl chloride can be used to make several esters, but with some alcohols, the
reaction is EXCEEDINGLY violent and some dilution is needed to make the
experiment safe.
Description:
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Add some acetyl chloride to methanol: The reaction is extremely violent, almost
explosive. THIS IS EXCEPTIONALLY DANGEROUS WHEN DONE IN MORE THAN DROP
QUANTITIES! In this experiment no ester was smelled, a big cloud of HCl-fume
was produced, masking all of the ester.
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Add some acetyl chloride to isopropyl alcohol, add this dropwise and do this,
until a slight excess of acetyl chloride is added: This reaction is somewhat
exothermic but not exceptionally violent. Quite some HCl is produced and this
gives rise to thick fumes. The ester can vaguely be smelled, but there is too
much pungent smell of HCl, excess acetylchloride and acetic acid.
Add some of water: Droplets of an insoluble liquid can be observed in the
liquid, there still is a pungent smell of HCl and acetic acid.
Add small amounts of NaHCO3, and shake after each addition, until no more
bubbles are produced on addition of the solid. In this way, the smell of the
acetic acid and HCl is neutralized, but the smell of the ester still can be
observed. After this treatment, a colorless liquid is obtained, with colorless
droplets in the liquid.
The isopropyl ester obtained in this reaction has a strong smell, but in lower
quantities, it is quite pleasant sweet, with a smell reminiscent of
strawberries.
The reaction, occuring in this experiment is
ROH + ClC(=O)CH3 --> ROC(=O)CH3 + HCl, here R is CH3- for methanol and
(CH3)2CH- for isopropyl alcohol.