Name: _______________________________________
Per: _____
Making Esters
I. Introduction
Esters are organic substance made by reacting ________________ with _______________. This
reaction is commonly referred to as an _______________________ Rx, which yields water and
can therefore classified as a _____________________ Rx
Esters display a variety of smells and fragrances and are used widely in cosmetics. The other
substance class that you encountered that displayed strong fragrances were
_________________ and ___________________________.
Naming esters rules: Esters do not have an own ending that is added to the basic hydrocarbon
skeleton. Instead their name is composed of an alkyl that stems from the ____________
component and carboxylate that stems from the ________________________.
Apparatus and chemicals: Careful this lab includes the use of strong acids like
concentrated sulfuric acid. Everybody has to use lab goggles and be very
careful!!!!
Smelling Chemicals: never smell chemicals by sticking your nose into a test tube.
Esters and their reactants can damage your mucus membrane. Hold approx 5
inches from your face then fan with a hand over the test tube opening toward
your nose.
II. Procedure
Each group will require: Eye protection, 3 x test tube, test tube rack, test tube holder,
300 ml beaker
1. Fill your 300 ml with about 150 ml of tap water and place on the hot plate, turn on high.
The water should get close to boiling but not boil…..
2. Label your test tubes 1-3 with a permanent marker. Put the correct amount of alcohol and carboxylic acid into
each test tube. Note the odor of the mixture in table 1.
Alcohol
Carboxylic acid
30 drops methanol
+
30 drops acetic acid
30 drops methanol
+
20 drops butyric acid
40 drops methanol
+
0.5 grams salicylic acid
Name: _______________________________________
Per: _____
3. Now, to your mixture, CAREFULLY add 10 drops of concentrated sulfuric acid (H2SO4). The H2SO4 acts as a
catalyst and a dehydrating agent which forces the condensation reaction between the alcohol and the
carboxylic acid.
4. Gently tap the tube to mix the reactants.
5. Heat for about 2 minutes in the water bath. Cover the bath with a cover. If your test tubes boil remove them
periodically to calm the Rx down.
6. Turn off the heat, remove the test tube and carefully smell (waft!) your newly-synthesized ester. If the odor
seems odd or too strong, dilute it in half with water. Dispose your ester down the drain with lots of water,
wash with soap and dry.
III. Results
1. Complete the table below
Rx
Alcohol
Acid
1
Methanol
Acetic Acid
2
Methanol
Butanoic
(butyric) acid
3
Methanol
Salicylic acid
Smell before
Rx
2. Ester Names and formulas
Now draw the Rx for 1 -3 and name the esters you formed.
Smell after Rx
Name: _______________________________________
Ester Name
Allyl hexanoate
Per: _____
Structure Odor or occurrence
pineapple
Benzyl acetate
pear, strawberry, jasmine
Bornyl acetate
pine tree flavor
Butyl butyrate
pineapple
Ethyl acetate
nail polish remover, model paint, model airplane glue
Ethyl butyrate
banana, pineapple, strawberry
Ethyl hexanoate
pineapple, waxy-green banana
Ethyl cinnamate
cinnamon
Ethyl formate
lemon, rum, strawberry
Ethyl heptanoate
apricot, cherry, grape, raspberry
Ethyl isovalerate
apple
Ethyl lactate
butter, cream
Ethyl nonanoate
grape
Ethyl pentanoate
apple
Geranyl acetate
Geranyl butyrate
Geranyl pentanoate
geranium
cherry
apple
Isobutyl acetate
cherry, raspberry, strawberry
Isobutyl formate
raspberry
Isoamyl acetate
pear, banana (flavoring in Pear drops)
Isopropyl acetate
fruity
Name: _______________________________________
Per: _____
Linalyl acetate
lavender, sage
Linalyl butyrate
peach
Linalyl formate
apple, peach
Methyl acetate
glue
Methyl anthranilate
grape, jasmine
Methyl benzoate
fruity, ylang ylang, feijoa
Methyl butyrate (methyl
butanoate)
pineapple, apple, strawberry
Methyl cinnamate
strawberry
Methyl pentanoate (methyl
valerate)
flowery
Methyl phenylacetate
honey
Methyl salicylate (oil of
wintergreen)
Modern root beer, wintergreen, Germolene and
Ralgex ointments (UK)
Nonyl caprylate
Octyl acetate
Octyl butyrate
orange
fruity-orange
parsnip
Amyl acetate (pentyl acetate)
apple, banana
Pentyl butyrate (amyl
butyrate)
Pentyl hexanoate (amyl
caproate)
Pentyl pentanoate (amyl
valerate)
apricot, pear, pineapple
apple, pineapple
apple
Propyl ethanoate
pear
Propyl isobutyrate
rum