Question

Extraction of Eugenol from Cloves ​

1.) Define co-distillation.

2.) What is the purpose of using steam to distill your product

3.) Why is it important to prevent the foam from entering your condenser?

4.) Why is it important to extract the aqueous layer 3 times (5mL) using methylene chloride? What would happen if you extracted one time using 15 mL of methylene chloride?

4.) Ferric (III) Chloride is a test to react with phenols. Write the equation of eugenol with ferric (III) chloride.

Answer 1

1. Co-distillation is a process in which a mixture of two compounds immisible with each other (generally both liquids) are seperated by the vertue of their bioling point. The mixture is heated to convert the liquids to their gasous state, suddenly cooled down using a distillation condenser (with a stream of cold water) and collected in a liquid form as a distillate. In case of Euganol, we are looking at a steam distillation technique, wherein, clove oil mixed with water is distilled using a steam.  
2. We are using steam to vaporize the clove oil. This is because clove oil (boiling point is as high as 200 ^oC) gets vaporized with the help of steam. The vapours get converted back to its liquid state and collected in a container.
3. It is important to avoid the foam formation in order to avoid the contamination of the distillation condenser. This may cause the solid to condense along with the pure liquid distillate.  
4. It is very important to extract the aqueous layer atleast 3 times as eugenol contains a phenolic group (slightly acidic in nature) which makes it to slightly dissolve in water. Few more extractions ensures the complete extraction of eugenol from aqeoues layer.
5. Please see the attached image for the answer.