Making Esters lab
In this lab, each group will be synthesizing an ester. There will be four
different esters being made. You are responsible to make one, and to
observe/smell the others that have been made by other groups. The
four reactions are:
1. salicylic acid and methanol
2. salicylic acid and 3-methylpentan-1-ol
3. benzoic acid and methanol
4. 3-methylpentan-1-ol and acetic acid
Procedure:
1. Half fill a 1 L beaker with hot water. Get a hotplate. Place the
beaker (with water) onto the hot plate and start heating. You
want to get it to a GENTLE boil.
2. There is a pipette for each reactant. DO NOT MIX THE PIPETTES.
You will need to wear your goggles from this point forward. Be
especially careful when handling chemicals because some are
concentrated, and corrosive. If any of these come in contact with
your skin, flush immediately with water.
3. Measure 1 mL of alcohol into a clean test tube. Add 10 drops of
carboxylic acid (or in the case of a solid, 1 small scoop—just
barely cover the end of the scoopula). Carefully add 4 drops of
sulfuric acid. Swirl to mix.
4. Stopper the flask firmly with
a cork stopper. Heat the flask
in the water bath. The
contents should be kept just
below their boiling point. If
boiling occurs, or liquid
begins to rise up the glass,
adjust the flask so it is not as
deep in the water. See
diagram for set up.
5. Heat for 10-15 minutes, then remove the test tube, put in the test
tube rack, and allow it to cool. You can run cool water along the
sides of the test tube. While you are waiting you can clean the
workstation or work on questions below.
6. Smell the product by fanning fumes towards your nose (do not
inhale directly).
7. You should smell each group’s product and record its scent.
8. WASH YOUR HANDS!
9. Clean up. All reactants should be placed in the waste bin provided
at the front of the classroom. Wash all glassware with soap and
water, and rinse well.
Analysis Questions
1. Draw the esterification reaction that occurred in each scenario (all
FOUR). Include all products and reactants, and names for
everything.
2. Name the scent of all four reactions.
3. What is the purpose of the sulfuric acid?
4. Why does it make sense that steam is observed on the test tube?