Experiment 7: Dehydration of Cyclohexanol
Positive Baeyer Test
purple ----> dark brown manganese dioxide precipitate
What is a Bromine test?
tests for the presence of unsaturation, phenols, and anilines.
What is a Baeyer test?
tests for unsaturation for determining the presence of carbon-carbon double-bonded compounds.
Bromine Test forms what compound?
trans-1,2-dibromocyclohexane
Baeyer test (potassium permanganate) tests for
unsaturation
____ is eliminated to form a _______ ______ ______bond
water; carbon-carbon pi
The good questions start here and below
-------------
3 Factors of Organic Rxns?
-each reactant dissolved in a solvent -one solution is added slowly to another -extothermic
Positive Bromine test
dark orange -----> clear
What apparatus is used in Dehydration of Cyclohexanol?
Fractional Distillation
How to increase sped of rxn if it is slow?
Heat it
How many moles of Water does it take to distill 2.2 moles of cyclohexanol?
1 mole of water!
What 2 factors promote elimination and increase total product (cyclohexene?)
1. Use acid with a poor nucleophile rxn. 2. High rxn temperature.
3 steps of acid-catalyzed dehydration?
1.protonation 2.dehydration 3.deprotonation
Fractional distillation apparatus
17 items used
What temp must the experiment be kept under to avoid distilling cyclohexanol as an azeotrope?
90 degrees
What happens during the Baeyer test?
A cyclic manganate ester is formed and then hydrolyzed into cis-1,2-cyclohexanediol
In what direction is the product being removed?
A foward direction makes the reaction occurs.
What do organic reactions usually have?
Competing pathways; yield more than one product
What is the Alcohol being dehydrated?
Cyclohexanol
What is the Alkene being produced?
Cyclohexene
Objective of Dehydration of Cyclohexanol
Dehydrate alcohol to produce alkenes.
What type of reaction is this lab?
Elimination
What principle will shift the rxn towards the product?
Le Chatelier's principle
Why is proton acid catalysis required?
OH is a poor leaving group
What does fractional distillation even do?
Separates a mixture into its component parts. Chemical compounds are separated by heating them to a temperature at which one or more fractions of the mixture will vaporize.
Wtf is an azeotrope?
a mixture of two liquids which has a constant boiling point and composition throughout distillation.