Experiment 10
Experiment 10
Experiment 10
Objective:
The main purpose of this paper is to synthesis adipic acid by oxidative cleavage
of cyclohexane
Introduction
In this experiment, we will synthesize adipic acid by oxidative cleavage of
cyclohexene. Several oxidizing agents can cleave the double bonds of alkenes.
Adipic acid is used commercially to synthesize nylon. The reaction between
adipic acid and 1,6-hexane diamine gives nylon, a polymer. This experiment
demonstrates the synthetic utility of potassium permanganate, in addition to
providing a simple chemical test for the presence of an alkene.
Procedure
Before we start the experiment we must take control of the reactance use along
with their proper volumetric measures which will be later used for calculation
Then, we may clamp the 100-mL RBF and attach a condenser vertically up.
Clamp the condenser and allow cold water to run through the condenser by
means of rubber tubing. Set the controller to 40 and gently reflux for 30 minutes
After refluxing for 30 minutes, allow the reaction mixture to air cool (rise the reflux
set up and remove the flask heater and let the reflux set up intact) for few
minutes.
Then we must remove the condenser and add 1.0 g of sodium bisulfite to the hot
reaction mixture by using a powder funnel. Swirl and stir the mixture for about 5
minutes and cool in an ice water bath to below room temperature.
After that, we may set up a Buchner funnel and Filter flask for vacuum filtration
as shown in Figure 10.2. Clamp the filter flask and place a filter paper in the
Buchner funnel so that it covers all the holes. And add approximately 2 mL of
water onto the filter paper slowly and apply vacuum and make sure that the filter
paper covers all the holes.
Then we should add 1 spatula full of celite (or decolorizing carbon or washed
carbon) to the reaction mixture in the 100 mL RBF. Mix it thoroughly, and filter
through the Buchner funnel. The filtrate must be colorless. Add 10 mL of water to
the 100-mL RBF to rinse it. Pour this 10 mL of water onto the brown solid (MnO₂)
in the Buchner funnel.
Then we have to transfer the liquid from the graduated cylinder to the clean 100-
mL RBF and set up simple distillation as shown in Figure 10.3. Use 100-mL
graduated cylinder as a receiving flask. Using flask heater and controller (set the
controller to 70) distill all except approximately 20 mL of liquid into a 100-mL
RBF. Distill off the water until 20 mL remains in the 100-mL RBF flask. Suppose
you start with 80 mL of solution in the RBF and you collect 60 mL distillate in the
graduated cylinder, the difference will be 20 mL left in the 100 mL RBF.
As soon as possible transfer the remaining 20 mL hot solution into a clean 100-
mL beaker. Cool this solution in an ice-water bath below room temperature.
Vacuum filter the mixture and wash with 2 mL of cold water to remove traces of
hydrochloric acid. Pour the acidic solution in the filter flask into the container
labeled "acid waste".
Reaction Mechanism
Observation:
Cyclohexene 2g 82 0.0243
(limiting Adipic Acid
reactant)
Actual Yield
Yield Percentage = ---------------------------- x 100
Theoretical Yield
Conclusion:
The Synthesis of Adipic Acid using this method with cyclohexane is convenient
and effective. Even though the Yield % in our experiment is lying somewhere
around half, this method could be carried out with more precision to obtain a
better result
Post Laboratory questions.
2. What are the oxidation states of manganese 'Mn' in KMnO4 and MnO₂?
3. Name one of the commercial uses of adipic acid.
Ans: Almost 90 % of adipic acid produced is used in the production of nylon 66.
4. Comment on the green chemistry of this experiment. That is, the nature and
amount of solvent (for example water, etc.), and atom economy (number of
atoms in the reactants versus products) in this experiment.