2. Prelaboratory Assignment
1. Draw the structure of the following compounds:
Acetyl chloride Acetyl salicylic acid
Acetic anhydride Salicylic acid
Acetamide
Acetyl Acetic Acetamide
chloride anhydride
3. Prelaboratory Assignment
1. Draw the structure of the following compounds:
Acetyl chloride Acetyl salicylic acid
Acetic anhydride Salicylic acid
Acetamide
Salicylic acid
Acetyl salicylic
acid (ASA)
4. Prelaboratory Assignment
2. What is the purpose of adding ferric chloride to the
filtrate of acetyl salicylic acid?
Ferric chloride is added as an indicator which detects the
presence of salicylic acid in the products.
When FeCl3 ionizes, Iron(III) forms complexes with phenolic
compounds, such as salicylic acid. The color of these
complexes range from red to purple.
5. Prelaboratory Assignment
3. How would you test for ammonia vapor in the
basic hydrolysis of amides?
Since it is the vapor that is being tested, the most reliable
method available would be to suspend a damp piece of
red litmus paper at the mouth of the test tube.
Ammonia vapor is basic and would thus turn the red litmus
paper blue upon exposure.
7. Results
Hydrolysis of Acetic Chloride
Observation
It became slightly warmer after 2 drops of Acetyl
Acetyl chloride chloride. It turned to a cloudy white solution after adding
AgNO3
•No temperature change
Acetic anhydride •No change on the appearance of solution after adding
AgNO3
Reactions of Esters
Observation
Acid Hydrolysis of Minimal amounts of ASA dissolved. When cooled
Acetyl Salicylic Acid crystals, removed through filtering formed. Solution
turned purple after addition of FeCl3.
Esterification Separation of layers after heating. Strong scent of
bananas.
8. Results
Reaction of Amides
Observation
The vapor of the solution changed the blue litmus paper
Acetamide + HCl to red. Smelled like vinegar
The red litmus paper turned blue. Pungent odor
Acetamide + NaOH
10. OBSERVATIONS
It became slightly warmer after 2
Acetyl chloride drops of Acetyl chloride
It turned to a cloudy white
solution after adding AgNO3
•No temperature change
Acetic anhydride •No change on the appearance of
solution after adding AgNO3
11.
12. Reaction of an Acyl Chloride with water
Acetyl Chloride
or ethanoyl chloride :
or acyl chloride
The Equation:
14. Acetic Acid and hydrogen chloride gas is produced - the
hydrogen coming from the -OH group, and the chlorine
from the Acetyl chloride.
Adding an acyl chloride to water produces the
corresponding carboxylic acid together with steamy
acidic fumes of hydrogen chloride.
15. The reaction is usually extremely vigorous at room
temperature.
Addition with AgNO3 produced a cloudy solution. The
precipitate formed is from the reaction between AgNO3
and HCl, forming AgCl3.
This is done to indicate that a halide ion is present, in this
case Cl
16. THE REACTION OF ACID ANHYDRIDES WITH WATER
Acetic anhydride
or ethanoic anhydride
:
Equation:
17. Acetic acid is formed as the second product rather than
hydrogen chloride gas.
18. The reactions are slower. Acid anhydrides aren't so
violently reactive as acyl chlorides
Ethanoic anhydride can’t be said to dissolve in water.
When Ethanoic anhydride reacts with water, it would give
Acetic acid.
19. The only difference is that Ethanoic acid (Acetic acid) is
produced as the second product of the reaction rather than
Hydrogen chloride
21. Results
Observation
Acid Hydrolysis Minimal amounts of ASA dissolved.
of Acetyl When cooled crystals, removed through
Salicylic Acid filtering formed. Solution turned purple
after addition of FeCl3.
Esterification Separation of layers. Strong scent of
bananas.
23. Acid Hydrolysis of Acetyl Salicylic Acid
Acetyl Acetic Acid
Salicylic Acid and Water
Salicylic Acid
The reaction can proceed either way depending in the
conditions.
At equilibrium, this reaction favors a high concentration of
SA and a very small one of ASA.
24. Acid Hydrolysis of Acetyl Salicylic Acid
Acetyl Acetic Acid
Salicylic Acid and Water
Salicylic Acid
Hydrolysis of acetylsalicylic acid is an equilibrium
reaction catalyzed by acid (as in this case) or by base.
Normally the hydrolysis is driven to the right by low pH,
as well as by losses of HOAc to the air.
25. Acid Hydrolysis of Acetyl Salicylic Acid
Addition of ferric chloride is done in order to detect
the presence of a phenolic group.
The purple coloration results fro the formation of
ferric salicylate complexes.
26. Esterification
Isopentyl alcohol Acetic acid Isoamyl Water
acetate
The aroma of bananas is due to the synthesis of
isoamyl acetate from isopentyl alcohol and acetic
acid.
28. Observations
• The vapor of the solution
changed the blue litmus
Acetamide + HCl paper to red
• Smelled like vinegar
• The red litmus paper
turned blue
Acetamide + NaOH • Pungent odor
31. Basic Hydrolysis
Acetamide
If Acetamide is heated with NaOH, ammonia gas is
given off and left with a solution containing sodium
ethanoate
Ammonia evolved
32. Acid Hydrolysis
Acetamide is heated with a dilute HCl ethanoic acid
is formed together with ammonium ions. The final
solution would contain ammonium chloride and
ethanoic acid.
Ammonia did not evolve, ammonium chloride was
present
33. With the addition of HCl on acetamide, it smelled like
vinegar since acetic acid was formed. The color of the
blue litmus paper turned red due to the acetic acid.
With the addition of NaOH, the color of the red litmus
paper turned blue indicating the basicity of the
substance since ammonia was formed.
