Download Name / Functional Group

AP Chemistry
Unit 11: Carbon Chemistry
Esterification Lab
Procedure:
1. Put on your goggles.
2. You need a water bath of approximately 60°C. Fill a 400 mL beaker about 1/3 full of tap water and
heat it to boiling by turning on the hot plate to “10”.
2. Place one spatula-tip of solid salicylic acid into the test tube (about ¼ tsp).
3. Add 20 drop of methanol (methyl alcohol).
Be careful, the alcohol is volatile and tends to pour out rather than drip.
4. Add two drops of concentrated sulfuric acid (be careful not to drop acid on your skin or the table).
5. Turn off the hot plate and add cool water to the beaker until it is 2/3 full.
Check the temperature of the water bath with the thermometer and adjust accordingly.
6. Place the test tube with the reaction mixture into the water bath for five minutes.
7. Remove the test tube and quickly dump the mixture into a plastic cup filled with tap water. Waft.
8. Cleanup:
 Pour the water in the plastic cup down the sink. Rinse. Throw away the plastic cup.
 Clean the test tube with soap and water (sink) and return it to the tray.
 Return your goggles to the cabinet.
Questions:
1. Draw structural formulas of the reactants:
salicylic acid
methyl alcohol
2.
Draw and name the products of this reaction:
3.
This reaction is very slow at room temperature. Explain the two things we did to speed up the
reaction.
4.
Concentrated sulfuric acid is a __ __ __ __ __ __ __ __ __ __ __ agent. It removes ___________.
5.
Why was Step 7 an effective way to separate the ester from the other components of the mixture?
Post-Lab Questions relating to the preparation of the Methyl Salicylate.
1. Why was warm water was used for the water bath for the reaction?
____________________________________________________________________________
2. What was the purpose of adding the sulfuric acid to the reaction mixture?
____________________________________________________________________________
3. What was the purpose of mixing the products of the esterification with water?
____________________________________________________________________________
4. Why would adding warm water, help you to smell the aroma of the methyl salicylate?
____________________________________________________________________________
5. Write the Chemical Reaction of the esterification that you performed today.
+
→
+
6. What kinds of chemical compounds are aspirin (acetyl salicylic acid) and methyl salicylate
(i.e., alcohols, aldehydes, ketones, acids, esters, amides, etc)? __________________
7. How would you describe the aroma of methyl salicylate? _____________________________
8. If you combine the organic acid, “butanoic acid” with the alcohol, “3-methyl-1-butanol”, you
produce an ester that has the aroma of a banana. Write the chemical reaction for this
esterification below:
9. Aspirin and methyl salicylate are both esters of salicylic acid. Do these two different
chemical compounds have any similar physiological actions? Describe one of their
physiological actions. _________________________________________________________
10. If you had actually weighed out 0.5 g of salicylic acid, (C7H6O3) what mass of methanol
would your require for complete reaction? (Show your work for the next three problems)
11. What mass of methyl salicylate product would you expect from the stoichiometry above?