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Fidaa Janoudi
Chemistry
Liz Schibuk
Synthetic Ester Lab
Purpose
The purpose of this lab is to learn the process by which food chemists synthesize artificial flavor.
Introduction
Chemistry is the study of all chemicals. Chemicals may seem like an extremely small
topic, but in reality it is huge. Chemicals are the base of chemistry. They lead the subject into
deeper aspects that pass on more knowledge. Part of the deeper aspects of chemistry is called
organic chemistry. Organic chemistry is all about chemistry related to the element carbon.
Organic chemistry breaks down to many topics as well.
Carbons bond with other elements in different ways. They also may include an important
aspect called a functional group. Functional groups are atoms or groups of atoms that we add to
hydrocarbons that give hydrocarbons extra elements that cause different properties.
Hydrocarbons are when a bunch of carbons that are bonded together, are also individually
bonded with hydrogen and/or another element. Some functional groups are alcohols, esters,
carboxylic acids, ketones, ethers, amines, and benzenes. They all have different properties that
make them unique and are very important especially for this specific lab. Esters, the main topic
for this lab, are part of the artificial flavors we will be making. Ester synthesis is when a
chemical reaction happens and an ester is formed. In order for ester synthesis to happen, an ester
must be formed.
Chemicals can be either natural or synthetic. The only difference is that natural chemicals
are found in nature and synthetic chemicals are made by hand. They are the same exact
compound, just one is natural and one is artificial. Artificial flavors are flavors that are created
by human hands and are not found in nature.
In order to make an artificial flavor, a chemical reaction must take place. There are two
types of chemical reactions. There is endothermic and there is exothermic. The difference
between the two is the endothermic reaction takes in heat while the reaction is taking place and
the exothermic reaction releases heat while the chemical reaction is taking place. They both start
off with a little bit of heat and then they either take in or release later on in the reaction. The
activation energy is the energy needed to start off the reaction. It will only work before the
product is made. Catalysts are used to speed up a chemical reaction and lessen the amount of
activation energy needed in a reaction.
Procedure
Wintergreen:
1. Add 6
drops of methyl
alcohol to the test tube that has
acid pre-measured.
2. Gently agitate the mixture.
3. Add 1 drop of concentrated sulfuric acid (H2SO4).
4. Gently agitate the mixture.
5. Place the test tube in a beaker of hot water for 3 minutes.
6. Add 15
drops of water.
7. Carefully smell the mixture, and record the smell.
Grape:
1. Add
2.
3.
4.
5.
6.
7.
Pear:
1.
2.
3.
4.
5.
6.
7.
8.
6
drops of methyl
alcohol to the test tube that has
acid pre-measured.
Gently agitate the mixture.
Add 1 drop of concentrated sulfuric acid (H2SO4).
Gently agitate the mixture.
Place the test tube in a beaker of hot water for 3 minutes.
Add 15
drops of water.
Carefully smell the mixture, and record the smell.
Add 6 drops of n-propyl
alcohol to a clean test tube.
Add 2
drops of glacial acetic acid.
Gently agitate the mixture.
Add 1 drop of concentrated sulfuric acid (H2SO4).
Gently agitate the mixture.
Place the test tube in a beaker of hot water for 3 minutes.
Add 20
drops of water.
Carefully smell the mixture, and record the smell.
Banana:
1. Add 6
drops of isamyl
alcohol to a clean test tube.
2. Add 2
drops of glacial acetic
acid.
3. Gently agitate the mixture.
4. Add 1 drop of concentrated sulfuric acid (H2SO4).
5. Gently agitate the mixture.
6. Place the test tube in a beaker of hot water for 3 minutes.
7. Add 20
drops of water.
salicylic
anthranilic
8. Carefully smell the mixture, and record the smell.
Orange:
1. Add 6
drops of octyl alcohol to a clean test tube.
2. Add 2
drops of
glacial acetic acid
acid.
3. Gently agitate the mixture.
4. Add 1 drop of concentrated sulfuric acid (H2SO4).
5. Gently agitate the mixture.
6. Place the test tube in a beaker of hot water for 3 minutes.
7. Add 20
drops of water.
8. Carefully smell the mixture, and record the smell.
Pineapple:
1. Add 6
drops of n-butyl
alcohol to a clean test tube.
2. Add 2
drops of butyric
acid.
3. Gently agitate the mixture.
4. Add 1 drop of concentrated sulfuric acid (H2SO4).
5. Gently agitate the mixture.
6. Place the test tube in a beaker of hot water for 3 minutes.
7. Add 20
drops of water.
8. Carefully smell the mixture, and record the smell.
Strawberry:
1. This reaction must take place in a fume hood because it uses a smelly compound called
butyric acid
.
2. Add 6
drops of
ethyl alcohol to a clean test tube.
3. Add 2
drops of
butyric acid.
4. Gently agitate the mixture.
5. Add 1 drop of concentrated sulfuric acid (H2SO4).
6. Gently agitate the mixture.
7. Place the test tube in a beaker of hot water for 3 minutes.
8. Add 20
drops of water.
9. Carefully smell the mixture, and record the smell.
Apple:
1. This reaction must take place in a fume hood because it uses a smelly compound called
butyric acid .
2. Add 6
drops of
methyl
alcohol to a clean test tube.
3. Add 2
drops of
butyric
acid.
4. Gently agitate the mixture.
5.
6.
7.
8.
9.
Add 1 drop of concentrated sulfuric acid (H2SO4).
Gently agitate the mixture.
Place the test tube in a beaker of hot water for 3 minutes.
Add 20
drops of water.
Carefully smell the mixture, and record the smell.
Results
REACTANTS
PRODUCT
FLAVOR
Carboxylic Acid Alcohol
Ester
Intended
Observed
Salicyclic Acid
Methyl Salicylate
Wintergreen
Wasn’t
observed.
Anthranilic Acid
Methyl Alcohol
Methyl Alcohol
Smelled like
burnt gloves.
Grape
Glacial Acetic
Acid
Wasn’t
observed.
N-propyl
Alcohol
Pear
Glacial Acetic
Acid
Isoamyl
Alcohol
Banana
Glacial Acetic
Acid
Octyl Alcohol
Orange
Smelled like
banana laffy
taffy.
Smelled like
a rotten
orange.
Butyric Acid
N-butyl Alcohol
Smelled like
a banana.
Pineapple
Butyric Acid
Ethyl Alcohol
Smelled like
bubble gum.
Strawberry
Butyric Acid
Methyl Alcohol
Apple
Analysis of Results
Part 1
Smelled like
French
cheese.
1. What evidence do you have that an ester was produced in each of your reactions?
An ester was produced in each reaction because after all of the carboxylic acids were added
to the alcohols; some bonds are broken and create two new bonds. One bond of water and one
bond of a new chemical including an ester. The evidence we have is that an ester is a double
bond oxygen that is bonded to another oxygen which is sandwiched in between the double bond
and a carbon.
2. What is the role of sulfuric acid in this reaction? How come it isn’t listed with the other
reactants?
The role of the sulfuric acid is the catalyst. It isn’t listed with the others because it does
not do anything that changes the actual chemical. It is only used to speed up the reaction
and lessen the amount of activation energy.
3. In your own words, describe what happens at a molecular level when an alcohol and a
carboxylic acid react.
When a carboxylic acid and an alcohol react, the bonds are broken and are switched
around to bonding into two different molecular bonds. One bond will contain the water
and the other bond will contain the newly formed product of the carboxylic acid and the
alcohol.
Conclusion
I.
Choose one of the mastery tasks listed at the beginning of the lab. Write a short
paragraph explaining how your work on this lab demonstrates mastery of that GSE.
One of the mastery tasks I showed complete mastery in for this lab is ester synthesis.
Before I started working on this lab report, ester synthesis was a little challenging. I asked peers
and relatives for a little more information about it. Although, as I was working for this lab, I
learned a whole lot more. I learned how to find esters, I learned how to write and complete
chemical reactions and esters and I learned that it wasn’t as hard as I thought. By the end of this
lab, I felt one hundred percent more comfortable in using ester synthesis and am very glad that I
had the opportunity to learn such an amazing topic.
II.
You and your little sister are at Stop and Shop with your mom. Your sister sees Grapples
for sale and shouts out: “That’s nasty! Apples that taste like grapes? That must be filled
with like mad chemicals. We should get the organic apples instead, I hear they don’t
have chemicals.”
Write a short paragraph in response to your sister. Your paragraph should demonstrate a
strong understanding of what "organic" means when speaking about agriculture, as well as
the difference between natural and artificial chemicals.
No, I think you have gotten the wrong understanding of this, little sister. Organic foods also have
chemicals as well. They may not be the same as regular farming chemicals use but they are still
chemicals. Chemicals are not bad, unless you are using them in the wrong way. There are two
different kinds of chemicals. There are natural chemicals and there are synthetic chemicals.
Natural chemicals are the types of chemicals that organic farmers use for their crops. They are
called natural because they are chemicals found in nature. Synthetic chemicals are the types of
chemicals that regular farmers use. They have the same exact molecular structure; the only
difference is that synthetic chemicals are made by hand. Grapples are apples that have a grape
flavor added to it. The grape flavor is made by hand, so it is an artificial chemical. The difference
between the organic apple and the grapple is the organic apple is fed with natural chemicals and
doesn’t have any flavoring in it and the grapple is an ordinary apple that does have artificial
flavoring in it. In conclusion, the difference is not which is healthier, it is which is natural and
which is artificial.
Appendix: Skeletal Structures for Alcohols and Carboxylic Acids Used in this Lab
Alcohol
Carboxylic Acid
Methyl
Salicylic Acid
n-Propyl
Isoamyl
Anthranilic Acid
Octyl
n-Butyl
Acetic Acid
Ethyl
Butyric Acid