Chem 234
Experiment 4: Steam Distillation
Introduction
The purpose of this experiment is to extract Eugenol from Cloves using steam distillation as a purification technique and to transfer Eugenol from the aqueous phase to the MeCl2 phase. With steam distillation, the boiling point of a mixture of immiscible liquids is lower than the boiling points of the individual components. Water from the steam is one of the components of an immiscible liquid mixture. The vapor pressures of each of the components during the distillation are additive. And, the outcome is a co-distilled mixture of water and immiscible components. The organic components can be separated from water.
Experimental
First we set up an apparatus for a direct method steam distillation, using a 500 mL three-necked round-bottomed flask. A 125 mL Erlenmeyer flask was used as a collection flask. Placed 7 g of clove buds/ground cloves into the flask and added 150 mL water. Began heating with a Bunsen burner to create a steady rate of distillation. While distilling, we continued to add water from the addition funnel, as needed, to maintain the level of the liquid in the distilling flask. Continued until 75 mL was collected. Chilled. Emptied the water from the addition funnel and placed the chilled distillate in it. Extract the distillate twice with 10 mL portions of CH2Cl2. Poured the Ch2Cl2 into the steam distillate, then gently swirled. Each time, filtered the lower layer through a small amount of anhydrous Na2SO4 into a single tared 50 mL Erlenmeyer flask with 1 boiling chip. Evaporated the solvent using a steam cone in the hood. Dried the outside of the flask and weighed. Calculated the weight-percent recovery of the oil from the original amount of cloves used. Then, we determined the infrared spectrum of the oil.
Results, Data, Calculations
Weight of empty boiling flask: 32.022g
Weight of flask with oil: 33.651g
Eugenol oil: 1.632g
Watch glass weight: 50.288g
Cloves: 7.011g
%
References: Infrared Spectroscopy notes, Dr. Etoga. March 5, 2012, Chem 234 class Mondays Chemistry 234 San Francisco State University Chemistry Manual 2012