Organic Chemistry Laboratory II, 10 February 2011
Introduction and Objectives
The purpose of this lab was to obtain a pure sample of clove oil from ground cloves using steam distillation, perform infrared spectroscopy on the sample, and analyze the IR to identify the major constituent in the clove oil. The first day the clove oil was removed from the ground cloves into an aqueous solution then removed from the water using DCM. The sample was left in a sealed container for one week and then isolated by drying the sample and removing the DCM. After the clove oil was isolated it was analyzed using IR spectroscopy.
Isolation of Clove Oil: The steam distillation apparatus …show more content…
15.0 mL of 1M aqueous sodium hydroxide was added to the clove oil in the separatory funnel. The bottom layer of the separatory funnel was removed and the top layer added to a 250 mL beaker. The aqueous bottom layer was then added back to the separatory funnel. 15.0 mL of 1M aqueous sodium hydroxide was added to the separatory funnel. The bottom layer was again removed and the top layer added to the previous 250 mL beaker. 10 mL of hydrochloric acid was added to the clove oil mixture which turned cloudy. A sample of the mixture was placed on the blue litmus paper which turned pink. The acidic solution was then added to the separatory funnel and 15.0 mL of DCM was added. The bottom layer of the separatory funnel was added to a 250 mL beaker. 15.0 mL of DCM was added again to the separatory funnel. The bottom layer was again added to the 250 mL beaker. A 100 mL round bottom flask and cork base were weighed at 104.356 g. Magnesium sulfate was added to the beaker until the powder stopped clumping together. The supernatant was decanted off into the pre-weighed 100 mL round bottom flask. The DCM was removed from the solution using a rotovap machine. The clove oil, round bottom flask, and cork base were weighed at 105.426 g. The clove oil was added to the IR spectroscopy machine and run. The results were obtained (Figure 1) and analyzed to find the major constituent. The weight of clove oil obtained …show more content…
When analyzing the IR, the first peak at 3515 cm-1 told me the compound contained an O-H bond which removed four of the six choices. The most prominent peak at 1515 cm-1 told me that the constituent contained aromatic C=H bonds which helped to identify that the constituent had a benzene ring. The peaks occurring 1650 cm-1 showed the constituent contained at least one C=C bond between Csp2 molecules (Figure 1). After elimination the last choice of the compounds using the IR, the major constituent of clove oil was identified as eugenol (Diagram