need a good hypothesis please should be disposed of in the aqueous waste contain
ID: 229546 • Letter: N
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need a good hypothesis please
should be disposed of in the aqueous waste container. NEVER DISASSEMBLE A HOT REACTION APPARATUS. Always allow the reflux apparatus to cool before disassembling Flash boiling could occur and you could get burned by splashing liquid or hot glass EXPERIMENTAL PROCEDURE Esterification reaction Bring a 25 mL round bottom flask containing a small magnetic stir bar or boiling stones to the fume hood. You should always place the round bottom flask in a beaker (250 mL beaker, depends on the size of the round bottom flask) for stability when carrying it around. Add 3.5 mL of isopropanol and 7 mL of acetic acid in the round bottom flask. You can use the same graduated cylinder for each measurement. With caution, using a graduated pipette slowly add -1.0 ml, of concentrated sulfuric acid (H2SO4) into the same flask. Sulfuric acid is toxic and corrosive; avoid getting it on your skin. Stopper the flask. Rinse the graduated cylinder immediately with water into the aqueous waste container; do not remove it from the hood before rinsing. Bring the reaction flask back to your bench, assemble a reflux apparatus, and adjust the heating to a gentle reflux Reflux the reaction for about 45 minutes. The timing should start once the reaction begins to boil. After the reflux is complete, remove the heat source by lowering the heating mantle away from the flask. Let the reaction flask cool for five minutes, and then cool it to room temperature using a cool water bath Extraction . Rinse the round Transfer the contents of the reaction flask into a 125 mL separatory funnel bottom flask with two 6 mL portions of water ether. Transfer the washes into the separatory funnel. Drain the aqueous layer into a beaker. Be sure to retain the organic layer, which contains the product mixture. Extract the product mixture a couple of times with 10 mL portions of 5 % aqueous sodium bicarbonate. Be sure to shake and vent the funnel frequently before draining the aqueous layer. Even though alcohol is the limiting reagent in this reaction, a small amount of alcohol may remain in the product mixture. The and then again with two 8 mL portions of diethyl unreacted alcohol and sulfuric acid should partition into the aqueous layer and removed from the product mixture. Collect the organic layer and dry it with a drying agent. UNIVERSITY ATALBANY State University of New York 102Explanation / Answer
Given example is acid catalyzed esterificatio reaction where isoopropyl acetate is obtained by condensation of acetic acid with isopropanol using sulfuric acid as the catalyst.
Product was obtained in good yields by extraction method with basic work up. Product was extracted in to diethyl ether and sulfuric acid and unreacted acetic acid, isopropanol went in aqueous layer. Small amount of acid left in diethyl ether layer was further removed by sodium bicarbonate work-up.
Purified isopropyl acetate was obtained in good yields by fractional distillation process since the different in boiling point of diethyl ether and isopropyl acetate is significant for isopropyl acetate to be purified by distillation. Diethyl ether being more volatile is collected first followed by isopropyl acetate.
Finally the product was characterized by IR spectroscopy where appearance of peak around 1730 cm-1 confirmed the ester synthesis. Additional proof for the esterification is disappearnce of OH stretching peaks around 3300 cm-1
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