Date of Completion of Experiment: Monday, November 19, 2012
Date Report Submitted: Monday, December 3, 2012
Objective of Experiment
The objective of this experiment was to learn the process of resolution of α-phenylethylamine. Materials
Compound| Molecular Weight (g/mol)| Melting Point (°C)| Amount used| Moles used| (+) Tartaric Acid| 150.087| 171–174| 11.9 g| 7.93 x 10-2| (+,-) α-phenylethylamine| 121.18| 184-186| 10.0 ml| 8.25 x 10-2|
In a 250 ml Erlenmeyer flask, (+) tartaric acid (11.9 g) was dissolved in 165 ml of methanol. This mixture was heated on a steam bath. Racemic (+,-) α-phenylethylamine was slowly added to mix well. Solution was allowed to cool for 15-20 minutes to observe crystallization of the salt. After observing the precipitate, prims formation that appeared like sand, the solution was corked and left at student lockers for a week. After a week, solution was poured from the crystals. Methanol (10 ml) was then added to the flask containing the crystals and. the accumulation of the crystals was broken down with a stirring rod. The crystals were collected by using a Bucher funnel with a filter paper, a rubber adaptor and a filter flask connected to a vacuum. Crystals were washed out of the flask with the filtrate and rinsed off on the funnel with 10 ml of methanol. Crystals were then spread on a paper towel to completely dry. Product was weighted and the percentage recovery of (-) amine(+) hydrogen tartrate was calculated. To recover (-) α- phenylethylamine, the crystals were placed in a 125 ml Erlenmeyer flask and 50 ml of 2N (8%) aqueous NaOH solution was added. The mixture was swirled until all the crystals dissolved. The solution was tested for basicity with litmus paper and then the sample was transferred to a separatory funnel. The flask was rinsed off with 10 ml of methylene chloride, which was also added to the separatory funnel. The stopper was placed...