Preparation of SyntheticBanana Oil Lab: synthesize isopentyl acetate by combinin
ID: 726570 • Letter: P
Question
Preparation of SyntheticBanana Oil Lab: synthesize isopentyl acetate by combiningisopentyl alcohol with acetic acid and sulfuric acid under refluxfor an hour.....So:Describe and explain how each of the folllowing experimentalerrors or variations might affect your results:
a) You failed to dry the reaction flask after washing it withwater
b) You forgot to add the sulfuric acid
c) You used twice the amount of acetic acid specified in theprocedure
d) You left out the sodium bicarbonate washing step
e) Thermometer bulb was 1cm higher than it should have been
Calculate the amount of isopentyl acetate that should be present in the reaction mixture at equilibrium based on 300 mmol of acetic acid and 150 mmol of isopentyl alcohol as starting quantities. Use equilibrium constant of 4.2 for this calculation. Moles can be used in place of concentration as volumes cancel out.
Explanation / Answer
(a) You failed to dry the reaction flask after washing it with water. If you forget to dry the flask then when you add the isopentyl alcohol to it, it will absorb the moisture causing its concentration to decrease and decreasing the rate of reaction. This in turn will cause the overall yield of isopentyl acetate to decrease. (b) You forgot to add the sulfuric acid Sulfuric acid is one of the main reactants of the esterification reaction. Without it the product of isopentyl acetate cannot be formed. (c) You used twice the amount of acetic acid The reaction will not be affected if too much acetic acid is used but more sodium bicarbonate would be needed to neutralize the extra acetic acid. The solution will dissolve more isopentyl acetate making the yield decrease. (d) You left out the sodium bicarbonate washing step If you leave out the sodium bicarbonate washing step then the sulfuric acid will react with the isopentyl acetate during the heating for distillation. This will result in the hydrolysis of the ester and will lead to lower yields of the ester. (e) Your thermometer bulb was 1 cm higher than it should have been. If the thermometer is placed 1 cm higher than it should have been, then it will be to far away from the boiling solution and the temperature will read inaccurately low. This would be a major source of product loss because you will not reach a high enough temperature for the distillation to complete. Therefore the yields of the ester will be lower.