Experiment 12: Dehydration of Cyclohexanol

water is eliminated from a _____ bond in an elimination reaction

pi

You cannot _______ separate an azeotrope via distillation

separate

why is protic acid catalysis needed?

-OH is a bad leaving group -looses protonated OH (water) to form carbocation (RDS)

Safety

-very strong dehydrating acid -chemical burns from bromine solution

Procedure

1. dehydrate cyclohexanol with dehydrating acid in microdistillation rig 2. wash distillate with NaCl 3. dry with calcium chloride 4. bromine test and permanganate test 5. IR spectra

which alcohols dehydrate most rapidly

3 > 2 > 1

minimum boiling azeotrope

Boiling point of two component system is lower than either individual component

Why keep distilling temp below 90?

Keep from distilling cyclohexanol (bp 98c in azeotrope with water)

azeotropes

a mixture of two liquids that has a constant boiling point and composition throughout distillation.