- 1 2 Pts Enter Your Experimental Data In The Following Table Be Sure To Include The Units 1 369 Mass Of Amine Left 1 (60.33 KiB) Viewed 75 times
- 1 2 Pts Enter Your Experimental Data In The Following Table Be Sure To Include The Units 1 369 Mass Of Amine Left 2 (60.33 KiB) Viewed 75 times
- 1 2 Pts Enter Your Experimental Data In The Following Table Be Sure To Include The Units 1 369 Mass Of Amine Left 3 (67.06 KiB) Viewed 75 times
mass of thr product 3.89 moles of the product 0.014 mol molar mass 271.26 gmol Prepare a solution of the resolved amine in cthanol, the concentration of which the councy stops and no further solvent appears to be coming of break the section at the pit by calculate the percent recovery. Measurement of the Optical Rotation determined. Record the mass of a clean (rinse only with ethanol to clean) 10-ml. volumetrie Talk Add your partners' resolved amines, and your resolved amine, to the volumetric flask and weigh again. Record the masses to the nearest oog Dilute carefully with ethanol until the volumes about 5 mm below the etched mark. Complete the dilution with Pasteur pipet up to the enched mark. Stopper the volumetric Nask securely and mix its contents thoroughly by menting and shaking. The resulting solution must be clear If your diluted solution is cloudy seek advice from your Teaching Assistant. Filter the cloudy solution through a tiny plug of cotton wool in a Pasteur pipet into another clean 10-ml. volumetric flask if it is necessary to remove any insoluble impurities. The volume will be somewhat less than 10 m. but do not dilute the solution further. Stopper the flask tightly. You are now ready to use the polarimeter to read the angle of rotation of your sample of resolved (-)-l-phenylethylamine. Each group will sign out a polarimeter tube. Rinse the tube with a tiny amount of the solution in your volumetric flask and then fill the tube completely with the solution. At this point the solution should be transparent and there should be no air bubbles. (The rest of the solution should be kept until all members of the group finish reading the sample) Remove any liquid and fingerprints from the outside of the end pieces of the polarimeter tube with a Kimwipe. Be sure that the two ends are clean. Insert the tube in the polarimeter and record the sample reading in your notebook Each of you should read it separately. Take the average of the three readings Empty your polarimeter tube and any liquid remaining in the volumetric flask into the Experiment 6 WASTE container. Rinse both the polarimeter tube and the volumetric flask with ethanol only under a fume hood and return both promptly. Notebook Calculation of the % Enantiomeric dicess (ce) • Calculate the specific rotation of your resolved amine as described in Technique 13- Polarimetry. The specific rotation of the pure resolved amine is (a} -- 403 • The % enantiomeric excess of the resolved amine (ce) can be calculated using the following expression: determined specific rotation % enantiomeric excess - * 100% specific rotation of pure amine The % enantiomeric excess, also called the optical purity, indicates how much in excess an is in a misturs. A racemic mixture, made up of equal amounts of nantiomers, has a antiomer is optically pure