Acetylsalicylic Acid

By: Lindsey

Acetylsalicylic acid is an odorless, white, crystalline solid.
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Chemical Properties/Physical Properties:

Acetylsalicylic Acid is an odorless, white, crystalline solid.The molecular Formula for Acetylsalicylic Acid is C9H8O4. The structural formula is CH3COOC6H4COOH. The molar Mass is 180.16 g/mol. The melting Point of Acetylsalicylic Acid is 136oC. And the boiling point is 140oC. The density of Acetylsalicylic Acid in it's normal state is 1.40 g/. Acetylsalicylic
Acid's solubility in water is 1g/100g water at 37oC. Acetylsalicylic Acid decomposes rapidly in solutions of ammonium acetate, carbonates, citrates, or hydroxides of the alkali metals. Acetylsalicylic Acid has a covalent bond because all the elements are in the nonmetallic family. The percentage composition by mass of Acetylsalicylic Acid is H-4.476% C-60.001% and O-35.523%. The percentage composition by number of Acetylsalicylic Acid is C-108.09702 (60.0%) H-8.063576 (4.5%) O-63.99772 (35.5%)

Background, Discovery:

It was originally derived from Salicin the active ingredient in Willow bark. Hippocrates, who lived sometime between 460 B.C and 377 B.C., left historical records of pain relief treatments, including the use of powder made from the bark and leaves of the willow tree to help heal headaches, pains and fevers. By, 1829, scientists discovered that it was the compound called salicin in willow plants which gave you the pain relief. In certain parts of the world Willow bark had been used for centuries in folk medicine. In 1897 Felix Hoffmann, an employee of Fredich Bayer, first prepared aspirin which is now the active ingredient in over 60 over-the-counter medicines.

Where is it found?/How is it obtained?

The average aspirin tablet contains about 325 milligrams of Acetylsalicylic Acid with an inert binding material such as starch. Acetylsalicylic Acid is a compound called Salicin made from boiling the bark and leaves of a white willow tree. It can be purchased as aspirin over the counter in pharmacies and grocery stores.You can also prepare aspirin (acetylsalicyilc acid) from Salicylic acid and acetic anhydride using the following reaction:
salicylic acid (C7H6O3) + acetic anhydride (C4H6O3) --> acetylsalicylic acid (C9H8O4) + acetic acid (C2H4O2)

Uses and Importance of Compound:

Acetylsalicylic Acid is a a non-steroidal anti-inflammatory drug (NSAID) used to treat pain, inflammation and fever. It is useful in the relief of headache and muscle and joint aches. Also, it is used to lower fevers and reduce inflammation, especially those caused by rhumatic fever and arthritis. It can thin the blood so in small doses, it can prevent heart attack, stroke & unstable angina. Since it has the ability to thin the blood Acetylsalic Acid will inhibit the form
ation of blood clots. Acetylsalicylic Acid interferes with the body's synthesis of specific Postaglandins. Postaglandins are a compound produced by almost every tissue in the body and control the substances involved in the the transmission of nerve impulses which participate in the body's defenses against infection.


The synthesis of aspirin is classified as an esterification reaction. Salicylic acid is treated with acetic anhydride, an acid derivative, causing a chemical reaction that turns salicylic acid's hydroxyl group into an ester group (R-OH → R-OCOCH3). This process yields aspirin and acetic acid, which is considered a byproduct of this reaction. Small amounts of sulfuric acid (and occasionally phosphoric acid) are almost always used as a catalyst. This method is commonly employed in undergraduate teaching labs.


Acetylsalicylic acid overdose can cause ringing in the ears, headache, dizziness, confusion, high fever and low blood sugar. Side effects can include; nausea, vomiting, diarrhea, gastrointestinal bleeding, respiratory disturbances (which can be fatal in children), vertigo, hallucinations, and it is linked to the development of Reye's syndrome.

3D Model: