Fischer Esterification Lab Report

Experiment: The Fischer Esterification Bella Giuffrida – Partners: Rori, Corinne, and Morgan Pre-Lab Questions: 1) Complete extraction scheme of product 2) No – esters are in fats and oils and the product should be an oil. Oils and fats do not dissolve in water well because water is polar and oil and fats are nonpolar. Therefore the ester formed (isopentyl acetate) would likely not dissolve in water well. 3) An excess of acetic acid is necessary because it shifts the favor in the reaction to the products. The reaction needs a substance to push it from equilibrium towards the desired ester. An alternative to this method would be using water (in excess) or isopentyl acetate in order to perform reverse fischer esterification to produce isopentyl alcohol and acetic acid. Background/Purpose: The purpose of this reaction is to produce an ester from an alcohol and a carboxylic acid. Isopentyl acetate and banana oil are the products of acetic acid and isopentyl alcohol with a catalyst (sulfuric acid) via Fischer esterificiation. The process involves heating, cooling, separation of organic and inorganic layers, and using the rotary evaporator. The final product is weighed out and an IR spectroscopy is taken as well. Main Reaction: Table of Physical Properties: Chemical Mol. Wt. (g) Density (g/mL) Melting point Isopentyl alcohol Acetic acid Sulfuric acid Isopentyl acetate Ether Brine Sodium bicarbonate Water 88.15 0.80 -117 Boiling point (C) 130 60.05 98.07 130.19 1.05 1.84 0.87 16.5 10 -78 117-118 290 142 74.12 58.44 84.01 0.71 ---2.20 -116 801 270 34.6 1461 ---- 18.02 1.00 32 100 Hazards/Precautions: Isopentyl alcohol – High concentrations can irritate eyes and respiratory tract. Acetic acid – may burn eyes and cause chest pain if exposed. Sulfuric acid – Will irritate eyes and skin if exposed and is corrosive to all body tissue. Inhalation can cause lung damage. Isopentyl acetate – Can be irritating to eyes, skin and respiratory tract if exposed. Ether – May cause irritation to skin and eyes and vapors may cause headaches and nausea. Sodium bicarbonate – may cause irritation to eyes and skin if exposed. Water – Not hazardous. Reaction Stoichiometry: Experimental Procedure: 1. Put sand in a thermowell and heated up with a powermite 2. Set up the condenser tube 3. Turned on the water to let it run through the condenser tube 4. Added 2 mL of isopentyl alcohol to a 25 mL round bottom flask 5. Zeroed the flask and added 4.30 g of acetic acid to the round bottom flask 6. Added 10 drop of sulfuric acid to the flask 7. Heated the solution in the thermowell with sand for 45 minutes after drops started forming 8. Cooled for 5 minutes at room temperature 9. Prepared an ice bath and cooled for an additional 5 minutes 10. Added water until the substance reached roughly 8 mL 11. Moved solution to a separatory funnel 12. Shook the funnel and let the layers separate 13. Discarded lower aqueous layer 14. Added 4 mL of ether and 4 mL of water to the separatory funnel 15. Shook us the funnel again and let aqueous layer drain 16. Added 2 mL of 5% aqueous NaCHO 3 17. drained the aqueous layer into another container 18. Washed organic layer by adding 2 mL of brine 19. hook funnel again and drained into a small beaker 20. Filtered solution through a filter of sodium sulfate, celite and cotton into a new 25 mL round bottom flask that weighed 75.02 g 21. Put the solution in a rotary evaporator 22. Weighed the flask with the final product to be 76.43g 23. Took an IR of the final product 24. Wafted the final product to see how it smells Results, Data and Calculations: Product: Isopentyl acetate, and an ester Observations: - As the reaction heated initially the color changed from orange to darker orange with a little bit of a brownish color to finishing with a lighter orange/gold color - The product smelled like bananas and a little like nail polish remover - The final product was a clear liquid IR Spectra: There is a carbonyl stretch and C-O stretch shown in the IR. There was no alcohol or carboxylic acid stretch in the experimental IR either. The experimental IR and given IR were very similar. Mass of product: 0.19g (101.60 g – 101.41 g = 0.19 g) Conclusion: All in all the experiment was successful because the desired product, ester, isopentyl acetate was produced through the process of performing Fischer esterification. The product was formed by combining acetic acid and isopentyl alcohol with a catalyst (sulfuric acid). After heating and cooling the chemicals a seperatory funnel was used to isolate the desired organic layer. The organic layer was transferred to a rotary evaporator to purify the product. When the IR was taken it showed no alcohol stretch, which was a positive sign that the correct product was formed. There was also a carbonyl and C-O stretch on the experimental IR that also showed up on the given IR, which is a good indicator, that isopentyl acetate was produced. Reverse Fischer esterification is a process that can also be used to work backwards from the results of this experiment. The products of this reaction because the reactants. Post-Lab Questions: 1) a. b. 2) Sulfuric acid is a catalyst in this reaction. Catalysts are not consumed by reactions they lower the activation energy for the reaction, by adding more of the catalyst to the reaction will cause no change to the results because of this fact. 3) In the case of reverse Fischer esterification the products would be the reactants that were used in this experiment, isopentyl alcohol and acetic acid. 4) The reactants did not have a strong odor, the products however had a stronger odor that was similar to a mixture of banana candy and nail polish remover