In this lab the synthesis, purification, and characterization of isoamyl acetate, or banana oil, was determined. The synthesis was completed by a reversible esterification reaction which required the heating of glacial acetic acid and isoamyl alcohol, combined with a sulfuric acid catalyst in hexane. In order to increase the efficiency of the reaction, LeChatelier’s Principle is utilized by removing water from the products. As a result, the reaction as a whole shifts the left producing more isoamyl acetate to try and balance the reaction once again. Once the product was collected, it was purified through means of fractional distillation. Finally to characterize the product, and assess its purity, IR and NMR spectroscopy were taken. Reaction:
Compound Name| Mol. Weight (g/mol)| Mass (g)| Moles| Equivalents| BP (°C)| Density (g/mL)| Global Acetic Acid| 60.05| 4.20| 6.99E-2| _____| 118°-119°| 1.049| Isoamyl Alcohol| 88.148| 6.08| 8.90E-2| _____| 131.1°| 0.8104| Isoamyl Acetate| 130.19| 2.23| 1.71E-2| 8.976| 142°| 130.19| Water| 18.01| 1.25| 6.94E-2| 1.241| 100°| 18.01|
Sulfuric Acid| 98.079| 1.84| 1.88E-2| ------| 69°| 1.84| Hexane| 86.18| 4.52| 5.24E-2| ------| 337°| 0.6548|
In a 50 mL round bottom flask, 7.5mL of Isoamyl Alcohol, 4.0 mL of 17.4M Glacial Acetic Acid, 1 mL of concentrated Sulfuric Acid, and 6.9 mL of Hexane were combined along with two boiling chips. A Dean-Stark trap was then assembled, and 1.25 mL of hexane was added to the trap and marked with a pen. The value used was predetermined in the pre-lab by stoichiometric calculations. The Dean-Star trap was attached to the flask and condenser, and was heated on an aluminum block until the flask started to reflux. As the contents were heated, the solution turned from a peach color to purplish red. In order to prevent loss of...