Steam Distillation of Clove Oil with solvent extraction experiment

Question 1

Main constituent of clove oil?

Answer 1

Eugenol , Contains a benzene ring in its structure

Question 2

How to extract clove oil from cloves?

Why is it extracted this way?

Why are whole cloves used, not powdered?

Answer 2

• Steam distillation

-Clove oil extracted at a temperature below its boiling point, to prevent the cloves from charring making it impossible to extract the oil

• Whole cloves contain more oil than powdered cloves.

Question 3

Steam Distillation

Answer 3

A method that uses the principle that when two immiscible liquids are together their boiling point is lower than either of the two pure compounds alone.

Question 4

Emulsion

Answer 4

colloid of two immiscible liquids
(oil drops dispersed throughout water)
creamy white liquid

Question 5

Steam distillation

Answer 5

-Water added to steam generator
-safety tube placed into steam generator, ensuring the bottom of the safety tube was well below the level of the water in the generator. The water should be topped up regularly
-Known mass of cloves placed in the pear shaped flask with some water.
-Bunsen burner on , steam passes through flask for 40mins.
-Clove oil emulsion passed through the condenser to the receiver, which is a separating funnel in this diagram. The emulsion has a milky colour.
- Emulsion cools in separating funnel

Question 6

Purpose of safety tube during steam distillation

Answer 6

• prevents build up of steam and avoids explosion.

Question 7

How to isolate clove oil from emulsion

Answer 7

solvent extraction

Cyclohexane added to emulsion in separating funnel and stoppered.
-shaken vigorously
-Invert funnel and release any built up pressure
-The lower aqueous solution collected in a beaker, upper organic layer placed into a separate labelled beaker .
- repeat with aqueous solution and extra cyclohexane 3x more to maximise oil yield.
- Add drying agent to beaker containing organic layer ( anhydrous sodium sulphate)
- Filter through filter paper to remove remaining water & drying agent.
-The solvent is then allowed evaporate off the filtrate overnight in fume cupboard
this leaves clove oil behind.

Question 8

Safety feature during solvent extraction

Answer 8

• Invert separating funnel & turn tap to release any pressure that may have built up during the shaking.