Cagatan, Jay Marie B.

BSN

Final Exam

Carbonyl: Aldehyde and Ketones

1. Write the structural formula and the IUPAC name of the following compounds that were used in
the experiment: Formaldehyde and Acetone.

Formaldehyde Acetone

2. In tabulated form, summarized the properties of the carbonyl compounds:

Properties of Carbonyl Compounds

1. They exhibit both positive and negative charge
2. Dissolves from other forms of polar molecules
3. These are to be polar in nature
4. Chemically reactive compounds or they control the reactions of a chemical reaction
5. Said to be polar molecules
6. Insoluble in water

3. The solubility in water and an organic solvent.

Compound Solubility
Water Insoluble in water
Organic Solvent Dissolves in other forms of polar molecules

4. Oxidation using Tollen’s Test, Fehling’s Test, Chromic acid Test, and Iodoform Test. Note if
the result is a positive result or not.

Compound Tollen’s Fehling’s Chromic Acid Iodoform

Positive Positive Positive
Aldehyde Negative
(Silver mirror) (Orange-red precipitate) (Green coloration)
Positive
Ketone Negative Negative Negative
(Yellow precipitate)
5. Based on the results tabulated, discuss what you have determined about the carbonyl
compounds, and include any additional concepts learned.

From the results tabulated, I have determined that the characteristics of the reactions of the
aldehydes and ketones occurs at the unsaturated carbonyl groups on the addition and oxidation
reactions. With the same reagent, aldehydes usually react faster than ketones, mainly because
there is less crowding at the carbonyl carbon and the steric effect. Aldehydes are also more easily
oxidized than ketones. On the other hand, the carbonyl group is responsible in the increased
melting point and boiling point of a compound. When in terms of solubility, the carbonyl group
are mostly insoluble to water but soluble in chemical solvents.

6. Why do aldehydes have the ability to be oxidized while ketone does not?

Aldehydes can be easily oxidised to carboxylic acids due to the presence of a hydrogen atom on
carbonyl group which can be easily converted to OH group. Since ketones do not have any
hydrogen atom attached to the carbonyl group, they cannot be oxidised easily, and therefore,
strong oxidising agents are required for this purpose.

7. What happens when an aldehyde is treated with Tollen’s reagent and with Fehling’s solution?
Show the chemical reaction of each test that would support your answers.

When an aldehyde is treated with Tollen’s reagent by dissolving silver nitrate and sodium
hydroxide to extract the red color and rendering the solution colorless by placing ammonium
hydroxide. Aldehydes contain hydrogen atoms that allows oxidation convenient and thus the
silver mirror image has been formed.

When an aldehyde is treated with Fehling’s solution, it would be tested by adding Fehling’s
solution to the mixture and then heated. Aldehydes are oxidized quickly by giving a red
precipitate as a positive result.
 Nomenclature

Carboxylic Acids and Esters

1. Write the structural formula of the following compounds that were used in the experiment:
acetic acid and benzoic acid.

2. In tabulated form, give the solubility in water, solubility in Base, and Acidity (pH Test) of
each sample in #1.

Compounds Solubility in Water Solubility in Base Acidity (pH Test)

Acetic Acid Miscible Miscible 2.4
Benzoic Acid Miscible in Boiling Water Miscible 2.5 - 4.0

3. What is saponification? Explain the process by giving examples/reactions.

Saponification is an exothermic chemical reaction, which means that it gives off heat that occurs
when fats or oils come into contact with lye, a base. In this reaction, the triglyceride units of fats
react with sodium hydroxide or potassium hydroxide and are converted to soap and glycerol.
4. Based on the results from the experiment, discuss what you know about the
properties/characteristics of carboxyl groups, and include any additional conclusions based on
your readings.

I discovered during the experiments that the carboxyl group contains an electro-negative oxygen
double bond to a carbon atom. As a consequence, the polarity of a bond would increase. A
carboxylic group compound will have a high melting point, hydrophilic centers and boiling
position. As a result of the formation of a solid and liquid hydrogen connection, one of the
typical examples is fatty acids, high melting and boiling point are removed. The atomic
properties of carboxyl groups therefore involve a double bond carbon atom linked to a single
bond of oxygen and hydroxyl, including acids such as acetate acid and amino acids which are
linked to a single bond.

5. Differentiate esters from carboxyl groups based on their physical characteristics.

Ester molecules are polar but have no hydrogen atom attached directly to an oxygen atom. They
are therefore incapable of engaging in intermolecular hydrogen bonding with one another and
thus have considerably lower boiling points than their isomeric carboxylic acids counterparts.
However, carboxyl group readily engages in hydrogen bonding with water molecules. The acids
with one to four carbon atoms are completely miscible with water, while esters borderline
solubility occurs in those molecules that have three to five carbon atoms.

6. What is esterification? Explain the process by giving examples/reactions.

The chemical reaction that takes place during the formation of the ester. The reaction happens
when carboxylic acids are heated with alcohols in the presence of an acid catalyst. The catalyst is
usually concentrated sulphuric acid. For example, reaction of ethanoic acid and propanol to form
propyl-ethanoate and water.

7. Identify the carboxylic acid and alcohol in which the ester below formed.

Extraction of Caffeine from Coffee

1. What is the formula for caffeine? Identify the functional group(s) present.

The formula for caffeine is C8HON4O2, it’s structure and functional groups present is:

2. Why caffeine is considered a drug?

Caffeine is considered a drug because it is a central nervous system stimulant which it speeds up
the message traveling between the brain and the body and causing it to increase alertness, energy
boost and elevates mood.

3. Give two examples of extraction in everyday life?

Making tea is a good example of extraction, in which humans do everyday. The water is placed
in contact with tea bags and tea is extracted from the tea leaves into the water. Another example
is decaffeination of coffee where the caffeine molecules are removed from the coffee beans.

***What is one thing that you learned while taking up this laboratory in Organic Chemistry? Is
there a new concept or idea, or did it modify/refine one you already have? If there’s a new idea,
how can you relate this idea to things you already know? If it is a modification/refinement, how
did your perception change? Be specific.

The one thing that I learned while taking up this laboratory in organic chemistry is that each type
of organic molecule has its own specific type of functional groups. Thus, it is fun and cool
naming compounds, combining its names to distinguish what type of compounds are they.
Though it was hard on the process, but eventually you’ll get there and you’ll be familiar on the
process. The detection of functional groups in an organic compounds is what I always thought
about because, through some other reagents and chemical reactions you can actually distinguish
what type of functional group a compound is. As a nursing student, the study of its structure,
name, properties and reaction is essential, especially when you would go to a medical course,
the knowledge from this subject would help you especially in medications and other aspects in
medicine. This would also help me assess and know other reactions in the human body and
apply my learnings on this subject.