Pre Lab Experiment 7: Isoamyl Acetate Flashcards
What are the starting materials needed for synthesis of an Isoamyl Acetate (ester)?
1) Isoamyl Alcohol
2) Glacial Acetic Acid (glacial = less than 1% water)
3) Sulphuric Acid (catalyst)
What are the safety precautions in this lab?
Concentrated Acids must be handled with care because they will cause severe burns
How fast do we add sulphuric acid?
Slowly
When heating the solution, how fast should the rate of refluxing be?
1 drop/sec
What type of reaction is this esterfication?
a nucleophilic addition to a carbonyl
What does a strong acid (sulphuric acid) do in this reaction?
It acts as a catalyst by activating the carbonyl and protonates the OH for a good leaving group
How do we name an ester (3 steps)?
1) Alcohol prefix - ISOAMYL alcohol
2) Carboxylic acid - ACETic acid
3) Ester (suffix) - ATE
ISOAMYL ACETATE
How do we isolate ester in this lab? What is this step called?
Workup step. We isolate the ester by extraction (separation) with water, then sodium bicarbonate, and then saturated NaCl. Litmus paper when removing bicarbonate layer.
Why do we add saturated NaCl?
To get rid of the emulsion line that forms. Saturated NaCl is less soluble in the organic layer than in water.
What safety precaution do we need to take into consideration when using sodium bicarbonate?
Bicarbonate and acid will release CO2 gas. Just swirl with no cap and do not shake vigorously
Why do we have to make sure no drying agent gets into the dried solution?
Drying agent will burn during distillation
Why do we only want the fraction between 130-140 degrees during distillation?
That is the fraction containing the isoamyl acetate because its boiling point is 142
What safety precaution do we need to be careful of during distillation?
Not to distill to dryness or else explosion will happen.
