Dehydration of Cyclohexanol
Add 10mL of Cyclohexanol
to a 50-mL round-bottomed flask.
Add 4 mL of phosphoric acid and 60 drops of sulfuric acid to the flask, and swirl the flask to
thoroughly mix its contents.
Add your magnetic stirring bar and assemble the flask for fractional distillation. Use a 50-mL
Erlenmeyer flask as your
receiver.
Heat the reaction mixture
at a setting of between 3 and 4, and collect all distillates, keeping the
head
temperature BELOW 90oC. (If not heated too strongly the reaction temperature remains below 80oC
for
most of the reaction period).
When
no more distillate is observed coming from the condenser, discontinue heating.
Transfer the distillate to a test tube, add 1-2 mL of saturated sodium chloride solution, and
shake the corked test tube
well and allow the layers to separate.
Remove the AQUEOUS
portion using a disposable pipet .
Transfer the ORGANIC layer to a dry 50-mL Erlenmeyer flask and add a spatula tip full of
anhydrous sodium sulfate.
Occasionally swirl the flask for the next two minutes.
After cooling, pour the
contents of the still pot down the sink in your hood, followed by lots of
water. Rinse and clean the flask in
your hood sink as well (this minimizes the amount of alkene getting into the
lab itself).
Test the distillate for
unsaturation using the Baeyer Test.
Pour the remainder of your alkene into the recovery bottle at the front of the room,
leaving the drying agent in the erlenmeyer flask.