Lab 12: Dehydration of Cyclohexanol
What should you do if you spill dehydrating acid on yourself?
Wash with sodium bicarbonate
Why can't you assume that a liquid that boils at a constant temperature is pure?
It could be an azetrope
In order to perform a bromine test on a compound, it must be treated with a dilute solution of bromine. Which of the following results will indicate the presence of an alkene?
the reddish color will disappear
What is the rate determining step?
The formation of the carbocation when the water molecule leaves
Solutions of potassium permanganate may cause chemical burns and unsightly stains on your skin. How should you clean off your hands?
Wash any affected area with soap and warm water
The rxns of bromine and of permanganate with cyclohexene both belong to which of the 4 general kinds of reactions?
addition
Why would concentrated HCl be a poor choice as the acid catalyst for formation of cyclohexene by dehydration of cyclohexanol?
if you use acids with good nucleophiles like Cl, Br, I - you end up with those in your product by either SN2 or SN1 to form chlorocyclohexanes. Also if you dehydrate the alcohol to cyclohexene the HCl can add across the double bond to make chlorocyclohexane.
Procedure for the dehydration of cyclohexanol?
1. cyclohexanol + dehydrating acid in a simple distillation 2. collect cyclohexanol from collection 3. put into pipet and remove the lower water layer 4. wash cyclohexene with water 5. wash with NaCl 6. CaCl2 7. bromine 8. potassium permanganate 9. IR
What should you do if you spill bromine on your skin?
Sodium thiol sulfate
Why is the acid catalyst necessary?
The OH is a very poor leaving group, but if you donate an H then it becomes OH2 and a very good leaving group
How can cyclohexene be distilled without distilling cyclohexanol?
cyclohexene and water form an azetrope which is able to have a boiling point of 71 which is much lower than the cyclohexanol
If concentrated sulfuric acid is spilled during the experiment, what is the proper procedure for cleaning the spill?
neutralize it with sodium bicarbonate
While diluting some concentrated HCl, a student accidentally got some of the acid on his/her bare hands. What is the appropriate response?
wash with soap and water
What is eliminated to form the carbon-carbon double bond
water
